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Historic,  archived  document 

Do  not  assume  content  reflects  current 
scientific  knowledge,  policies,  or  practices 


U.  S.  DEPARTMENT   OF   AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY      RULLKTIN  No, 

I     O  HOWARD,  Entomologul  ind  Chid  ol  1 


THE  CHINCH  BUG 


BY 


v.  m.  webster; 

In  Charge  ofCerealand  Forage-Plant  Insect  Investigations. 


Issued  Jink  21,  1907. 


WASHINGTON: 

80YERNMEN1     PRINTING     OFFICE 

1 9  0 T. 


BUREAU  OF  i:\TOMOLOGY. 

L.  O.  Howard.  Entomologist  and  Chief  of  Bureau. 

C.  L.  Mablatt,  Entomologist  and  Acting  Chief  in  absence  of  Chief. 

R.  S.  Clifton.  Chief  clerk. 

F.  II.  Chittenden,  in  charge  of  breeding  experiments. 

A.  I).  Hopkins,  in  charge  of  forest  insect  investigations. 

W.  I).  Hunter,  in  charge  of  cotton  boll  weevil  investigations. 

A.  L.  Quatntance,  in  charge  of  deciduous-fruit  insect  in  rest igations. 

K.  F.  Phillips,  in  charge  of  apiculture. 

D.  M.  Rogers,  in  charge  of  gipsy  and  brown-tail  moth  work. 

A.  \V.  Morrill,  engaged  in  white  flit  investigations. 

]•;.  s.  G.  Titus,  in  charge  of  gipsy  moth  laboratory. 

C.  J.  Gilliss,  engaged  in  silk  investigations* 

R.  P.  CuBRiE,  assistant  in  charge  of  editorial  work. 

Mabel  Colcobd,  librarian. 

Cereal  and  Forage-Plant  Insect  Investigation's. 

F.  M.  Websteb,  in  charge. 

G.-I.  Reeves,  W.  J.  Phillips,  C.  N.  Ainslie,  special  field  agents. 


U.  S.  DEPARTMENT   OF   AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY      BULLETIN  No.  69. 

L  O.  HOWARD.  Entomologist  and  Chief  of  Bureau. 


THE  CHINCH  BUG. 


BY 


F.  M.  WEBSTER, 

In  <  harge  of  Cereal  and  Forage-Plant  Insect  Investigations. 


Issued  June  21,  1907. 


WASHINGTON: 

GOVERNMENT     PRINTING    OFFICE, 

L907. 


LF/lTHR  OF  TRANSMITTAL 


U.  S.  Department  of  Agriculture, 

Bureau  of  Entomology, 
Washington,  D.  C,  March  5,  1907. 
Sir:  I  have  the  honor  to  transmit  for  publication  the  accompanying 
manuscript  entitled  *'  The  Chinch  Bug,"  by  F.  M.  Webster,  in  charge 
pi  the  cereal  and  forage-plant  insect  investigations  of  this  Bureau. 
This  is  a  thorough  revision  by  Mr.  Webster  of  his  earlier  account  of 
thi-  destructive  pest  published  in  1898  as  Bulletin  No.  15,  neAV  series, 
pf  this  office,  and  includes  additional  data  based  on  observations  made 
during  the  past  eight  or  nine  }rears.  I  recommend  that  it  be  pub- 
lished as  Bulletin  No.  69  of  the  Bureau  of  Entomology. 

Respectfully, 

L.  O.  Howard, 
Entomologist  and  Chief  of  Bureau. 
Hon.  James  Wilson, 

Secretary  of  Agriculture. 

3 


CONTENTS 


Page; 

Distribution '•» 

Hibernation     10 

Spring,  su miner,  and   autumn   migrations 18 

Oviposition 20 

Egg  period  and  number  of  eggs  deposited  by  each  female 20 

Descriptions  of  the  differenl  stages  of  developmenl 21 

Development  and  habits  of  tin*  young 22 

Number  of  generations  annually 25 

Destructiveness  largely  due  to  gregarious  habits 28 

Food    plants 2<i 

Insects  that  are  mistaken  for  chinch  bugs 31 

Losses  caused  by  chinch  bugs :'».'! 

Natural  checks 36 

Influence  of  precipitation  on  the  chinch  bug 3G 

Inilnence  of  temperature  on  the  chinch  bug 43 

Natural  enemies 44 

Parasitic  fungi 44 

Fungous  enemies  of  the  chinch  bug  determined 46 

Field  and  laboratory  experiments  in  Indiana 47 

First  field  applications  of  fungous  enemies  of  the  chinch  bug 51 

The  work  of  Professor  Snow  in  Kansas 51 

Other  insects  attacked  by  Sporotrichum  globuliferum 53 

First  artificial  cultivations  of  Sporotrichum  globuliferum 54 

Results  of  field  applications  in  Ohio 54 

Meteorological   influences  favoring  development  of  fungous  ene- 
mies of  the  chinch  bug 56 

A  bacterial  enemy  of  the  chinch  bug f>7 

The  practical  utility  of  fungous  and  bacterial  enemies  in  fighting  the 

chinch  bug 58 

The  bobwhite  or  quail 58 

Other  bird  enemies  of  the  chinch  bug : 59 

The  frog 59 

Invertebrate  enemies  of  the  chinch  bug GO 

Remedial  and  preventive  measures 60 

Destruction  of  chinch  bugs  while  in  hibernation 01 

Sowing  decoy  plats  of  attractive  grains  or  grasses  in  early  spring 62 

Difficulty  of  reaching  chinch  bugs  in  meadows 02 

Watchfulness  necessary  during  protracted  periods  of  drought <;:; 

Utility  of  kerosene  in  fighting  chinch  bugs t;i 

Utility  of  deeply  plowed  furrows  supplemented  by  the  use  of  kerosene 

emulsion 65 

The  surface  and  coal-tar  method 65 

5 


b  CONTENTS. 

Remedial  and  preventive  measures— Continued.  Page. 

The  ridge  and  coal-tar  method r,<; 

Other  barrier  methods 68 

Necessity   for  preventing  chinch  bugs  from  becoming  established  in 

fields  of  wheal  and  grass 69 

Summary  of  remedial  and  preventive  measures 72 

Probable  origin  and  diffusion  of  the  chinch  hug 72 

Indications  of  a  probable  distant  origin  and  later  diffusion 74 

Unique  appearance  and  gregarious  habit 74 

Occurrence  <>f  the  long  and  short  winged  forms  and  their  distrilniti  >n_  7."i 

Relation  <>f  the  inland  and  seacoast  short-winged  forms 7^ 

Probable  course  of  diffusion 7^ 

Habits  of  the  European  species.  Blissus  doria  Ferr_   83 

Previous  ideas  on  the  diffusion  of  the  chinch  b  lg s7 

Reasons  for  the  present  theory  of  diffusion 

Index 91 


LLUSTRATIONS. 


Page. 

Fig.  1.— Map  of  North  America  showing  areas  Infested  by  the  chinch  lmg_  11 

2. —  [mmature  stages  of  t  he  chinch  bug 21 

:>. — missus  leucopterus:  adult  of  long-winged  form 22 

4. — missus  leucopterus:  adults  of  short-winged  form 2:5 

5. — Com  plant  infested  with  chinch  bugs 30 

6. — Nysius  angustatus 31 

T. — Piesma  cinerea 32 

8. — Corimela  na    pulicaria 33 

9. — Brachyrhynchus  granulatus:  larva,  pupa,  and  adults 33 

1<». — Map  showing  areas  in  the  United  States  over  which  the  chinch 
hug  occurs  iu  greatest  abundance  and  may  at  any  time  become 

destructive 35 

11. — Map  showing  distribution  of  the  chinch  bug  in  Ohio  in  189G 37 

12.- — Map  showing  distribution  of  the  chinch  bug  in  Ohio  in  1897 38 

13. — Map  showing  distribution  of  the  chinch  bug  in  Ohio  in  1894 39 

14. — Map  showing  distribution  of  the  chinch  bug  in  Ohio  in  1895  and 

amount  of  precipitation  over  the  State  during  May,  1895 40 

15. — Triphleps  insidiosus 60 

16. — Mili/us  cinctus 60 

17.- — Map  showing  probable  course  of  diffusion  of  the  chinch  bug  over 

North    America 79 

18. — Blissus  dorice:  immature  stages 83 

10. — Blissus    doriw:  adults 84 


tiik  chinch  lire. 


Few  insects,  and  certainly  no  other  species  of  t ho  natural  order  to 
which  this  one  belongs,  have  caused  such  enormous  pecuniary  losses  as 
lias  the  chinch  bug,  Blissus  leucopterus  Say.  Nbother  insect  native  to 
the  Western  Hemisphere  has  spread  its  devastating  hordes  over  a 
wider  area  of  country  with  more  fatal  effects  to  the  staple  grains  of 
North  America  than  has  this  one.  But  for  the  extreme  susceptibility 
of  the  very  young  to  destruction  by  drenching  rains  and  to  the  less 
though  not  insignificant  destructiveness  during  rainy  seasons  of  the 
parasitic  fungus, Sporotrichum  globuliferum  Speg.,on  both  the  adults 
and  young,  the  practice  of  raising  grain  year  after  year  on  the  same 
areas,  as  followed  in  the  United  States,  would  become  altogether  un- 
profitable. Some  of  this  insect's  own  habits,  emphasizing  as  they  do 
the  effects  of  meteorological  conditions,  are  the  most  potent  influences 
that  serve  to  hold  it  within  bounds,  by  giving  its  tendency  to' exces- 
sive increase  a  decidedly  spasmodic  character. 

DISTRIBUTION. 

The  genus  Blissus  is  widely  distributed  over  the  world,  occurring  in 
South  Africa.  Abyssinia.  Algeria,  Sicilia,  southern  Europe,  northward 
at  least  to  the  sand  dunes  of  central  and  northern  Hungary,  India, 
Japan,  southern  Russia,  and  in  the  Western  Hemisphere  in  Buenos 
Aires,  and  from  Panama  and  the  Island  of  St.  Vincent  northward 
to  middle  California  on  the  Pacific  coast  and  Cape  Breton  on  the 
Atlantic.  When  we  come  to  understand  that  the  Hemiptera  of  the 
world  are  far  from  being  well  known,  and  the  faunas  of  South 
America  and  central  Africa  have  as  yet  been  hardly  studied  at  all. 
we  may  well  presume  that  future  studies  of  the  hemipterous  insects 
of  these  countries  may  unite  some  of  the  different  areas  now  known 
to  be  inhabited  by  the  several  species  of  this  genus. 

At  present  in  tin1  Old  World  this  genus  may  be  said  to  occur  in  the 
Ethiopian,  Oriental,  and  Palanirctic  life  regions;  while  in  the  New 
World  it  ranges  from  the  Neotropical  region  at  Panama  and  St. 
Vincent  into  the  Nearctic  over  the  borders  of  the  Boreal  subregion  in 
British  America. 

Our  American. species,  BUssus  leucopterus  Say,  the  only  one  of  the 
genus  at  present  known  in  the  Western  Hemisphere,  has  been  recorded 
from  St.  Vincent  and  Grenada,  Wesl  Indies, by  rider;  Cuba, by  Stal; 

9 


10  THE    CHINCH    BUG. 

Volcan  de  Chiriqui,  Bugaba,  and  San  Feliz,  Panama,  by  Champion; 
San  Geronimo,  Paso  Antonio.  Panzos,  Champerico,  and  Rio  Xaranjo, 
Guatemala,  by  Champion;  Lower  Purissima,  Lower  California,  by 
(Jhler;  Alameda,  Cal.,  by  Koebele;  and  in  the  vicinity  of  San  Fran- 
cisco, Cal.,  by  both  Uhler  and  Koebele;  Orizaba.  Mexico,  by  H.  H. 
Smith;  Tamaulipas,  Mexico,  by  Uhler;  Mesilla  Park.  X.  Mex.,  by 
Cockerell;  Florida,  by  Schwarz  and  Dr.  J.  C.  Neal;  Sydney.  Cape 
Breton,  by  W.  II.  Harrington;  Muskoka,  Ontario.  Canada,  by  E.  P. 
Van  Duzee,  and  Winnipeg,  Manitoba,  where  a  single  specimen  was 
collected  by  Dr.  James  Fletcher  and  given  by  him  to  Mr.  Harring- 
ton, to  whom  I  am  indebted  for  information  regarding  it-  occurrence. 
Inland,  in  the  United  States,i1  may  be  said  to  be  generally  distributed 
from  Texas  to  Manitoba.  It  is  also  very  probable  that  its  occurrence 
along  the  Pacific  coast  ls  much  more  extended  than  is  at  present 
known,  as  it  has  not  been  searched  for  to  any  extent  in  that  region. 
(  See  map.  fig.  1.) 

HIBERNATION. 

The  chinch  bug  hibernates  in  the  adult  stage,  and  though  there  may 
be  occasional  exceptions,  especially  in  the  South,  it  has  yet  to  be 
observed  in  very  early  spring  in  any  other  than  the  adult  stage,  at 
least  in  any  locality  north  of  Mexico.  The  writer  observed  pupa-  in 
central  Illinois  apparently  in  hibernation  in  company  with  adults 
on  November  11,  but  there  is  no  proof  that  these  survived  the  suc- 
ceeding winter.  In  Tensas  Parish,  La.,  adults  were  abroad  in  con- 
siderable numbers  during  March.  1887,  yet  there  was  no  indication 
of  any  young  having  wintered  over.  The  adults  were  pairing  and 
seemingly  engaged  in  oviposition.  precisely  as  is  to  be  observed  in 
the  Northern  State-  during  May  and  June.  No  young  were  observed, 
as  most  certainly  would  have  been  the  case  had  they  occurred  there. 
for  observations  were  made  in  fields  of  young  corn,  where,  had  the 
young  bug-  been  present  even  in  very  limited  numbers,  they  would 
certainly  not  have  escaped  the  rigid  searching  under  and  about  the 
bases  of  the  leaves  of  the  young  corn  plant-. 

Doctor  I  low  anl "  quotes  Prof.  ( i.  V.  Atkinson,  at  that  time  of  Chapel 
Hill,  N.  C,  as  having  observed  half-grown  chinch  bugs  on  crab  grass, 
about  the  Lst  of  ( October.  The  same  authority  also  quotes  Doctor  Riley 
to  the  effect  that  many  of  the  chinch  bugs  pair  in  the  fall  preparatory 
to  -••.•king  winter  quarters,  and  also  cites  the  fact  that  Mr.  dame-  ( ). 
Alwood  observed  them  pairing  in  a  field  of  uncut  pearl  millet,  Octo- 
ber 27,  lss~.  on  the  ground-  of  the  Ohio  Agricultural  Experiment 
Station,  then  at   Columbus,  Ohio.     Dr.  Cyrus  Thomas,6  in  -peaking 


»The  Chinch  Bug,  by  I..  <  >.  Howard;   Reporl  of  the  Commissioner  of  Agricul- 
ture for  Hi.'  year  1887,  pp.  51   88. 
&  Bulletin  No.  5,  r.  S.  entomological  Commission,  j>.  13. 


HIBERN  \  I  lux. 


11 


of  tli*'  possibilities  of  an  occasional  third  brood  in  southern  [llinois 
and  Kentucky,  states  thai  there  were  some  evidences  of  tin-.  I>nt  not 


Fi<..  l.  —  M:i|i  <\  North  America  showing  distribution  of  til''  chinch  bug.       Author's  illustration.) 

sufficient  to  justify  him  in  asserting  it  as  a  fuel  or  to  satisfy  him  of 
it-  correctness. 


12  THE    CHINCH    RUG. 

It  therefore  seems  probable  that  no  young  arc  produced  as  a  result 
of  the  late  pairing,  at  least  until  spring,  ami  it  has  vet  to  be  shown 
that  the  lat<-  appearing  larva-  do  not  mature  before  the  hibernating 
season  sets  in.  or  else  die  during  the  winter.  When  we  come  t<>  con- 
sider the  extreme  susceptibility  of  the  newly  hatched  chinch  bug  t<> 
wet  weather,  less  perhaps  in  case  of  the  short-winged  form,  it  will  he 
apparent  that  as  we  approach  the  Tropic-  the  wet  ami  dry  seasons 
would  tend  to  influence  the  breeding  seasons,  a-  those  individuals  that 
hatched  before  the  close  of  the  rainy  season  would  he.  in  a  measure  at 
least,  continually  eliminated,  while  those  that  hatched  so  late  as  to  he 
caught  in  the  commencement  of  the  rainy  season  would  also  he  to  an 
equal  extent  destroyed,  and  thus,  by  continually  restricting  the  breed- 
ing period  to  certain  month-,  establish  a  fixed  law  that  would  he  ad- 
hered to  even  under  the  somewhat  different  condition-  which  occur 
farther  to  the  northward.  Unfortunately  the  date  or  date-  on  which 
the  young  were  observed  by  Mr.  Champion,  on  Volcan  de  Chiriqui, 
in  Panama,  are  unknown  to  the  writer,  and  it  i-  impossible  to  say 
w  let  her  or  not  they  were  found  during  or  near  the  dry  season. 

In  an  article  on  the  hibernation  of  the  chinch  bug,  Mr.  C.  L.  Mar- 
ian call-  particular  attention  to  the  fact  that  in  Kansas  the  chinch 
bug  in  autumn  seek-  the  dense  stools  of  some  of  the  wild  grasses  in 
which  to  hibernate,  and  to  such  an  extent  did  this  occur  that  it  was 
suggested  as  probably  the  normal  hibernating  habit  of  the  species. 

Before  entering  into  a  discussion  of  this  matter,  it  will  be  well  to 
present  two  communications  received  from  the  late  Dr.  J.  C.  Xeal.  at 
that  time  of  Stillwater.  Okla.  As  Doctor  Xeal  was  located  in  a  sec- 
tion of  the  country  where,  in  many  cases,  civilization  had  not  in- 
fluenced to  such  a  marked  degree  the  natural  insect  fauna,  the  author 
applied  to  him  to  secure  some  exact  information  in  regard  to  the 
chinch  bug  under  such  conditions.  The  correspondence,  however. 
was  terminated  suddenly  by  Doctor  Neal's  death.  The  two  letter- 
here  given  are  among  the  last  he  ever  penned.  They  are  of  a  some- 
what general  nature,  and  will  be  referred  to  later  in  this  discussion. 

Oklahoma  Agbich  ltubal  and  Mechanical  College. 

Stillwater,  Okla.,  October  .,'/.  1895. 

My  I  Mai:  Sii:  :  Years  of  the  28th  ]*US1  received.  Lnsi  year  was  the  firsl  wheat 
year  in  most  of  the  new  additions  to  this  Territory,  and  from  all  sections  the 
cry  was  for  infection,  as  "the  bugs  are  ruining  us."  I  received  letters  from 
every  county  in  the  strip  and  in  the  western  sections.  The  most  damage  was 
done  in  the  extreme  southern  range  of  counties,  and  near  Okarche  1  see  map. 
fig.  10)  the  damage  was  excessive.  I  do  net  think  there  is  a  single  acre  in  this 
er  Indian  Territory  thai  is  net  saturated,  so  t«>  speak,  with  the  chinch  bug. 
You  may  put  this  whole  area  down  as  within  the  infested  boundary  line. 
My  belief  is  thai  the  increase  of  country  roads,  the  decrease  of  March  Ores, 
tlie  shiftless  habits  of  the  vast  majority  of  our  farmers  in  allowing  volunteer 

sed  Life,  Vol.  VII.  pp.  'iwi  234,  L894. 


HIBERNATION.  13 

wheal  and  oats  to  grow  and  wheat  lands  i<»  remain  fallow,  and  the  planting 
of  new  and  better  grass  crops  than  the  tough  blue-stem,  are  direcl  causes  of 
what  I  believe  a  decided  Increase  of  this  Insect  in  Oklahoma  during  tin-  last 
Ave  years.  It  would  be  amusing,  if  it  were  not  so  pathetic,  to  read  the  mam 
letters  I  get,  something  in  this  wise:  "  I  planted  wheat  on  sod  land;  the  chinch 
bugs  destroyed  it  so  badly  that  in  February  I  plowed  it  tip  and  sowed  oats; 
this,  too.  went  the  same  way;  I  then  planted  corn,  and  when  it  was  ;i  foot  high 
the  little  bugs  came  by  the  millions  and  destroyed  that  ;  1  then  planted  the  land 
to  Kafir  corn,  and  that  will  be  ruined  if  you  can  not  help  inc."  What  could  I 
do  for  such  a  man'.'  Had  the  bugs  laid  out  a  programme  lor  their  daily  SUS 
tenance,  no  better  commissary-general  could  have  been  obtained  for  them  than 
he  was.  and  1  had  to  write  hint  that  his  plan  was  the  worst  one  possible  fol- 
ium, and  the  host  for  the  bugs,  and  that  the  only  suggestion  1  could  make. 
from  the  bugs'  standpoint  and  for  their  benefit,  would  he  to  plant  wheat  again 
so  that  they  could  have  something  for  the  coming  winter's  food,  in  his  case 
it  was  a  series  of  fatal  mistakes  from  ignorance  of  the  habits  of  the  bn^s. 

Another  thing  which  I  believe  adds  materially  to  the  increase  of  these  pests 
is  the  complete  destruction  of  the  prairie  chickens,  the  decimation  of  par 
bridges,  and  the  thinning  out  of  all  kinds  of  smaller  birds,  such  as  the  cow  black- 
birds, hank  sparrows,  martins,  larks,  and  other  prairie  birds.  This  section 
is  full  of  reckless  hoys  and  men  wdio  kill  everything  that  Hies,  good,  had.  and 
indifferent,  "  for  fun." 

Some  years  ago  I  wont  out  on  the  Cherokee  Strip,  miles  away  from  human 
habitation,  and  saw  some  of  the  small  birds — larks  and  killdees — busily  picking 
in  the  young  grass,  in  early  spring,  and  upon  examination  found  these  places 
swarming  with  chinch  bugs  sucking  the  juices  of  the  blue-stem  grass. 

Almost  any  time  in  the  winter  when  the  weather  is  warm  one  can  find  chinch 
bugs,  and  I  have  witnessed  two  "  flights"  of  these  insects  and  determined  them. 
I  should  he  glad  to  answer  any  more  specific  questions  at  any  time. 
With  regards,  I  remain, 

J.  C.  Neal. 

The  second  letter  is  a  short  note  in  reply  to  the  author's  question 
regarding  the  grasses  fed  upon  by  the  chinch  bug,  their  hibernating 
habits,  and  developments : 

Stillwater,  Okla..  November  20,  1895. 

Deab  Professor  Webstee:  In  reply  to  your  postal,  I  would  say  that  1  do  not 
know,  hut  will  at  once  make  observations  and  report  at  my  earliest  chance. 

My  belief  is  thai  the  bugs  attack  all  the  grass  family  except  the  Tendinis, 
and  that  only  is  exempt  on  account  of  its  hitter  taste,  which  effectually  shields 
it  from  insects,  as  far  as  I  have  seen,  both  in  this  section  and  in  Florida. 

I  will  take  the  matter  in  hand  at  as  early  a  date  as  possible  and  write  you 
progress  and   results. 

Very  respectfully.  J.  ('.  Neal. 

It  is  reasonable  to  infer  from  these  letters  that  the  chinch  bug  win- 
tered over  about  the  stools  <>f  grass,  and  that  the  birds  were  observed 

to  attack  them  there  in  early  spring,  a-  the  statement  is  made  that 
later,  when   the  young  com   was  a    foot    high,  the  little  bugs  came  by 

the  million.  This  condition  of  affairs  may  '>••  considered  in  conned  ion 
with  the  statements  of  Dr.  Asa   Fitch,0  regarding  his  observations 

a  Second  Report  on  Noxious,  Beneficial,  and  Other  Insects  of  New  York,  p.  283. 


14  THE    CHINCH    BUG. 

in  Illinois  iii  the  autumn  of  L854,  when  in  passing  over  the  northern 
part  of  the  State  he  found  the  ground  in  some  places,  in  the  midst 
of  extensive  prairies,  covered  and  swarming  with  chinch  bugs, 
reminding  him,  as  he  says,  "of  the  appearance  presented  on  parting 
the  hair  on  a  calf  that  ha-  been  poorly  wintered,  where  the  -kin  is 
found  literally  alive  with  vermin."'  Further  along  in  his  report 
i  J..  290)  he  -tate-  that  "so  late  a-  the  forepart  of  October  I  met 
several  of  these  insects  in  the  pupa  state,  and  some  of  these  I  do  not 
d(.ii!)t  would  pa—  the  winter  in  that  state,  and  therefore  would  not 
deposit  their  eggs  until  the  following  spring."  That  he  did  not  find 
these  pupa'  in  New  York  i-  shown  by  Ins  statement  on  page  -_>s7  of  the 
same  report,  to  the  effect  that  lie  had  "met  with  hut  three  specimens 
in  New  York,  occurring  on  willow-  in  the  spring  of  1847  and  May 
L2,  L851."  A-  shown  farther  on  in  this  bulletin,  there  i-  no  proof 
that  these  pupa'  did  not  develop  to  adult-  before  winter,  or  die  before 
spring,  and  the  conditions  indicated  would  almost  presuppose  that 
hibernation  would  take  pjace  on  the  prairies  where  the  insect-  were 
observed  by  Doctor-  Fitch  and  Neal.  From  personal  recollection 
the  writer  know-  that  the  section  of  Illinois  to  which  Doctor  Fitch 
refers  was,  at  the  time  mentioned,  hut  thinly  populated,  and  there 
were  -till  very  extensive  tracts  of  the  original  prairie  grasses  miles 
distant  from  woodland-. 

In  an  interesting  note  by  Mr.  F.  A.  Schwarz  °  on  the  hibernation  of 
the  chinch  bug,  given  in  discussing  Mr.  Marian'-  paper,  previously 
mentioned,  attention  is  called  to  the  fact  that  the  hibernation  of  the 
chinch  bug  had  been  observed  by  him,  in  its  maritime  home,  in  the 
vicinity  of  Fortress  Monroe.  Ya..  which  locality  he  had  been  in  the 
habit  of  vdsiting  for  a  number  of  year-,  during  the  first  warm  days 
of  spring.  The  maritime  flora  and  fauna  are  here  late  to  awake,  and 
ni(i-t  insects  peculiar  to  the  seacoast  can  -till  be  found  in  their  Winter 
quarters  by  the  end  of  April.  By  pulling  up  any  good-sized  stool  of 
Lira--  and  beating  it  out  on  the  smooth  surface  of  the  sand  or  over  a 
cloth  a  multitude  of  various  insects  are  -tire  to  be  found,  and  among 
them  always  plenty  of  chinch  bug.-.  These  stools  of  grass  not  only 
serve  a-  winter  quarters,  but  in  summer  the  chinch  bug-  crawl  into 
them  during  the  daytime  to  protect  themselves  from  the  fierce  ray-  of 
the  -mi. 

In  lie'  timothy  meadow-  of  northeastern  Ohio  the  writer  has  wit- 
nessed eases  where  the  chinch  bin:-  had  commenced  their  operations 
along  one  side,  worked  part  way  across  the  field,  killing  the  timothy 
a-  they  advanced,  and  continued  their  depredation-  the  following 
year  precisely  where  they  suspended  work  the  autumn  before,  the 
long-winged  individuals  only  migrating  in  the  intervening  time. 


',-■ 


[nsect  Life,  Vol.   VII,  pp.    120-422,   L895. 


HIKKKNATION.  15 

In  southwestern  Maine,  where  this  short-winged  form  has  oc 
curred  in  more  or  less  destructive  numbers  for  upward  of  forty  years, 
and  where  it  affects  timothy  in  the  Mime  manner  a>  in  Ohio,  I >< >t h  long 
and  short  winged  individuals,  the  latter  in  the  majority,  hibernate 
under  dead  leaves,  brush  heaps,  and  similar  debris  in  and  about  the 
fields  where  they  have  ravaged  the  timothy.  They  do  not  appear  to 
-elect  only  the  drier  portions  of  Mich  held-,  but  are  found  also  liter- 
ally swarming  about  the  clumps  of  rushes  (Juncus)  that  grow  in  the 
low  -pots.  Some  o\'  these  low  places  become  submerged  in  winter  by 
rains  and  melting  -now-,  and  the  hibernating  bugs  are  washed  out 
and  killed."  Possibly  others  not  observed  might  have  remained 
among  the  living  timothy,  as  it  is  further  stated  that  many  hibernat- 
ing individuals  were  to  he  found  among  the  leaves  of  clover  border- 
ing on  spots  of  timothy  that  had  been  killed  out  by  them  during  the 
preceding  summer. 

That  the  short-winged  or  maritime  form  must  hibernate  in  or  in 
very  close  proximity  to  the  field  it  infests  goes  without  saying,  and 
it  would  appear  that  hut  for  the  cultivation  of  timothy  it  would 
have  become  diffused  inland  from  the  coast  less  rapidly,  if  at  all. 
It  i-  doubtful  if  this  inland  diffusion  began  until  the  country  became 
settled  by  the  white4  man  and  timothy  began  to  be  grown  by  him  as 
a  forage'  crop — a  situation  that  would  be  coexistent  with  a  diminu- 
tion in  the  number  and  extent  of  prairie  and  forest  fires. 

West  of  the1  Allegheny  Mountains  we  encounter  this  short-winged 
maritime  form  only  in  western  Pennsylvania,  northern  Ohio,  south- 
ern Michigan,  extreme  northern  Indiana,  and  equally  extreme  north- 
ern Illinois.  The  writer  once  found  a  single  short-winged  individual 
in  southern  Ohio,  and  a  single  individual  that  may  or  may  not  belong- 
to  this  species  has  been  recorded  from  New  Mexico  by  Prof.  T.  D.  A. 
Cockereli: 

Except  as  indicated  in  the  preceding  paragraph,  over  this  whole 
country  the  long-winged  form  is  the  only  one  known,  and  its  habits 
are  almost  as  unlike  those  of  the  maritime  form  as  the}7  would  be 
were  the  latter  a  different  insect.  Timothy  culture  has  never  ex- 
tended to  the  Gulf  coast,  and  the  extensive  growing  of  the  crop  over 
this  whole  western  country  is  of  recent  date,  coexistent  with  the 
advent  of  the  white  man.  Here,  therefore,  timothy  is  not  attacked 
by  chinch  bug-. 

The  inland  or  long-winged  form  inhabits  largely  a  prairie  country, 
and  it  would  appear  that,  as  these  piairies  were  annually  burned 
over  during  the  hibernating  season,  the  form  that  became  the  most 
scattered  prior  to  hibernation  would  be  likely  to  stand  the  best  chance 
of  surviving.     It   seems  to  the  writer  that   the  wing-  of  the  chinch 

a  Nineteenth  Ann.  Rept.  Maine  Agric.  Exp.  Sta.,  me:;,  pp.   H-52. 


]C)  THE    CHINCH    BUG. 

bug  might  have  been,  in  early  days  in  the  Mississippi  Valley,  kept 
up  to  a  high  standard  of  development  by  the  necessity  of  such  an 
escape  from  prairie  fires  and  not  by  the  presence  of  Sporotrichum 
globuliferum^  as  suggested  by  Professor  Sajo  in  his  paper,  a  trans- 
lation of  which  is  included  herein  under  the  heading,  "  Habits  of 
the  European  species,  Blisms  dories  Ferr." 

A.s  mentioned  farther  on,  the  advance  of  civilization  having  revo- 
lutionized the  face  of  the  country,  there  has  conic  a  corresponding 
change  in  the  hibernating  habits  of  the  chinch  bug.  This  insect 
must  now  seek  shelter  in  the  limited  patches  of  timber  that  are  left 
in  the  sections  that  were  cure  entirely  wooded  and  in  the  matted  grass 
along  fences  and  roadsides,  but  especially  among  the  fallen  leaves 
and  rubbish  that  usually  accumulate  along  Osage  orange  hedges. 
Brush  piles,  old  haycock-,  strawstacks,  and.  in  Ohio,  at  any  rate. 
shocks  of  corn  fodder  left  standing  in  the  fields  through  the  winter, 
all  harbor  chinch  bugs  during  the  hibernating  season. 

The  fact  that  the  insect  hibernates  in  matted  bluegrass  along  road- 
sides and  fence-  has  been  called  in  question  by  Professor  Forbes  and 
by  Mr.  Marlatt,  the  former  in  his  first  report  as  State  entomologist 
of  Illinois  (p.  37)  and  the  latter  in  Insect  Life  (Vol.  VII.  p.  232), 
but  notwithstanding  this,  in  some  parts  of  Ohio,  in  Indiana,  and 
Qlinois  they  do  hibernate  in  just  such  places  and  can  be  found  there. 
especially  during  the  winter  and  early  spring  following  a  season  of 
abundance,  but  the  investigator  must  know  how  to  search  for  them. 
The  writer  has  found  them  late  in  the  fall  collected  under  rail-,  half 
buried  in  -oil  and  dead  grass,  and  in  northern  Illinois,  while  search- 
ing for  other  insects  in  early  spring,  he  was  sure  to  find  them  in  vary- 
ing number-  with  -mall  Carabidae,  Staphylinidse,  and  other  early 
appearing  insects,  on  the  under  side  of  boards  laid  down  in  grassy 
place.-,  though  no  amount  of  searching  the  grass  itself  would  have 
iv\ ealed  their  presence. 

In  the  timothy  meadow-  of  northeastern  Ohio  the  percentage  of 
long-winged  individuals  i-  always  much  greater  in  fall  than  in  June. 
showing  that  some,  at  least,  hibernate  there  and  migrati  to  the  cul- 
tivated fields  in  spring.  In  Maine,  in  the  case  of  the  maritime  form. 
of  565  bug-  collected  in  hibernation  in  October,  1002.  only  60  had  long 
wing-.  In  Kansas,  where  Mr.  Marlatt  made  his  observation-,  there 
was  -till  too  much  prairie,  and  the  species  was  doubtless  still  adhering 
to  it-  ancient  habit-  of  hibernation.  In  southern  Ohio  the  author  has 
found  it  attacking  the  wheat  in  May.  in  -mall  isolated  -pot-  over 
the  fields,  while  there  was  nothing  in  the  least  to  imply  an  invasion 
from  outside,  but  the  wheat  had  been  sown  in  the  fall  among  corn, 
and  later  the  cornstalks  cut  oil'  and  -hocked,  remaining  in  this  condi- 
tion  until   the   following  spring.     This  occurred  so  frequently  that 

ol9th  Rept  Maine  Agric.  Exp.  Sta.,  1903,  p.  4S. 


HIBERNATION.  17 

there  seemed  n<>  room  to  doubl  that  the  attacks  had  been  caused  by 
adults  wintering  over  in  the  corn  fodder,  and  dial  these  left  their 
winter  quarters  in  spring  to  feed  and  breed  on   the  grain  growing 

pearesl  al  hand. 

Prof.  Herbert  Osborn,0  in  giving  a  summary  of  his  observations 

on  (he  chinch  bug  in  Iowa  in  L894,  states  (hat  "  In  a  greal  majority 
*)\'  cases,  90  |>er  cent  or  more,  (he  infested  fields  were  directly  adja- 
cent to  hedges  or  thickets  or  belts  of  timber,  and  in  7.')  percent  Osage 
orange  hedges  were  the  most  available  shelter.  In  about  L3  per  cent 
of  the  cases  (he  evidence  showed  hibernation  in  grass  and  weeds,  and 
in  some  of  these  cases  there  could  scarcely  he  a  doubt  thai  the  hiber 
nating  bugs  were  protected  by  a  heavy  growth  of  grass  or  weeds  and 
that  they  moved  from  these  directly  into  the  adjacent  grain  fields." 
Prof.  Lawrence  Bruner  had  previously  called  attention  to  the  fad 
thai  the  chinch  bug  hibernated  in  great  numbers  about  Osage  orange 
hedges  in  Nebraska.  Doctor  Lugger,  in  Minnesota,  gives  the  follow- 
ing as  offering  shelter  to  the  bugs  during  winter:  "Rubbish  of  all 
kinds,  but  chiefly  that  of  hedges,  wind-breaks,  and  along  the  edges 
of  wood-,  a-  well  as  corn  fodder,  logs,  and  even  loose  bark  and 
-tone-." 

While  drenching  rain-  are  beyond  all  possible  doubt  fatal  to  the 
new  ly  hatched  young,  the  adult  bugs  seem  to  be  almost  proof  against 
either  wet  or  cold  weather.  It  is  doubtless  true  that  very  many 
individuals  die  in  their  winter  quarters,  and  in  fact  the  writer  has 
found  these  dead  in  considerable  numbers  in  some  instances  during 
early  spring,  but  it  seems  at  least  doubtful  if  either  cold  or  wet  would 
entirely  account  for  this  fatality.  It  would  seem  that  somewhere 
and  at  some  period  in  the  past  this  hibernation  has  been  more  for 
protect  ion  from  natural  enemies  than  against  the  elements,  though 
of  course  (here  might  have  been  other  reasons  not  discernible  under 
a  changed  environment.  The  pupa  hides  away  to  molt,  though  it 
d<.(-  not  appear  thai  this  course  is  folloAved  in  the  earlier  stages,  and 
the  reasons  for  this  are  not  at  all  clear.  That  the  adult  is  able  to 
withstand  combined  cold  and  wet  weather  is  amply  proved  by  the 
observations  of  several  people.  Dr.  Ily.  Shinier,  in  Illinois,  found 
thai  those  which  were  in  corn  husks  filled  with  ice,  even  the  chinch 
bug-  themselves  being  inclosed  in  the  crystallized  element,  were  able 
to  run  about  when  they  were  thawed  out.  apparently  unaffected  by  a 
.temperature  that  had  varied  from  15°  (o  20°  below  zero  Fahr.  1( 
seemed  (hat  when  exposed  to  (he  sweeping  prairie  winds  al  that 
temperature,  with  no  protecting  cover,  (hey  perished.  Mr.  (J.  A. 
Waters,  in  (he  Farmer-'  Review  for  October  li>.  L887,  relate-  that  a 
bunch  of  fodder  that   had   fallen  into  a  ditch  washed  out  near  a  corn 

"Cliin.li  Bug  Observations  in  [owa  in  L894,  Insect  Life,  Vol.  VII.  i»i».  230  232. 
26608— No.  69—07  m 2 


1  S  THE    CHINCH    BUG. 

-hock  by  heavy  rain-  became  covered  with  water  that  stood  over 
n  long  enough  for  a  sheet  of  ice  to  form.  When  the  water  had  sub- 
sided the  corn  was  husked  and  a  uumber  of  chinch  bugs  were  found 
among  the  car-,  where  they  had  been  immersed  for  a  week-  or  more; 
yei  on  being  exposed  to  the  warm  sun  they  began  to  crawl  about  in 
a  lively  manner. 

The  .Maine  Agricultural  Experiment  Station  some  year-  ago"  ear- 
ned out  a  -eric-  of  experiments  with  the  maritime  form  to  determine 
the  effect  of  freezing.  Ten  long-winged  ami  6  short-winged  bugs 
were  frozen  in  an  open  box  for  fifteen  hour-.  Upon  thawing  out  '1 
gave  no  signs  of  life.  After  being  kept  for  nine  hour-  at  a  tempera- 
ture of  65  the  1  1  surviving  bugs  were  refrozen  for  fifteen  hours  and 
then  thawed  out.  when  '>  long-winged  and  3  short-winged  revived. 
After  nine  hours  at  a  temperature  of  65°  they  were  fro/en  a  third 
time  for  fifteen  hour.-,  during  which  time  the  minimum  temperature 
sank  to  1G°  below  zero.  When  thawed  out  all  revived,  but  during 
the  following  nine  hours  at  65°  temperature  the  3  short-winged  bugs 
and  '2  of  the  loner-winged  one-  died.  The  remaining  3  long-winged 
were  then  frozen  a  fourth  time'  for  fifteen  hours,  after  which  none 
re\  ived. 

In  summarizing  the  results  of  these  experiments.  25  in  number, 
it  was  found  that  complete  submersion  in  water,  even  for  a  considera- 
ble period,  is  not  necessarily  fatal.  Freezing  during  submersion  in 
water  i-  almost  surely  fatal.  Freezing  while  exposed  to  dry  atmos- 
phere i-  generally  fatal.  Freezing  in  a  moisture-laden  atmosphere 
is  only  occasionally  fatal.  It  will  be  observed,  however,  that  not  all 
of  these  results  would  necessarily  follow  corresponding  experiments 
with  the  inland  long-winged  form. 

SPRING,  SUMMER,  AND  AUTUMN  MIGRATIONS. 

If  there  is  an  ample  supply  of  proper  food  close  at  hand  the  chinch 
hug  -imply  crawl-  from  it-  hibernating  place,  hut  if  it  is  in  the  timo- 
thy meadows  of  northeastern  Ohio  it  does  nothing  but  continue  it> 
ravages  where  it  left  off  the  autumn  before,  except  some  of  the 
long-winged  form,  which  very  evidently  fly  to  the  wheat  and  corn 
fields.  In  wheat  lields — unless  the  migration  has  been  from  an  ad- 
joining field,  in  which  case  the  attack  i-  made  along  the  edge  nearest 
thereto  -the  females  do  not  seem  to  forsake  their  gregarious  habits 
entirely,  a-  they  do  Dot  scatter  out  evenly  over  the  entire  field,  hut  ap-" 
pear  to  locate  in  colonies,  and  when  the  young  hatch  and  begin  to  attack 
the  growing  grain  their  presence  is  first  disclosed  by  small  whitening 
patches,  which  increase  in  dimensions  a-  the  young  heroine  older  and 
more  numerous.      In  low-lying  fields  these  whitening  patches  more 

Nineteenth  Rept  .Main-  Agric.  Exp.  Sta.,   L903,  p.  48. 


SPRING,  SUMMER,  AND    A.UTUMH    MIGRATIONS,  1<) 

commonly  appear  on  the  back  furrows  or  on  any  slight  elevations 
that  occur  in  the  field.  But  on  higher  and  level  ground  the  whitening 
area-  arc  observed  scattered  over  the  entire  field,  and  constantly 
widening  until  the  whole  Held  appears  to  ripen  prematurely  and 
crinkle  down.  When  the  migration  is  accomplished  by  crawling, 
the  females  seem  to  spread  only  enough  to  afford  food  for  the  young 
until  the  latter  are  able  to  make  their  own  way  from  place  to  place. 
The  young  remain  clustered  on  the  plant  about  which  they  were 
hatched  until  this  has  been  drained  of  sap,  when  they  make  their  way, 
almost  in  a  body,  to  a  second  plant,  and  in  this  way  an  attack  will  be 
pushed  forward  day  after  day. 

In  the  spring  the  chinch  bug  probably  lingers  about  its  winter  quar- 
ters until  a  favorable  day  for  migration  occurs.  Transfer  a  typical 
Indian  summer  day  to  early  May.  and  perhaps  raise  the  tempera- 
ture a  few  degrees,  and  you  have  a  day  during  which  chinch  bugs 
may  be  seen  on  the  wing,  crawling  along  on  fences,  or  at  rest  on  the 
top-  of  fence  po>ts  as  if  taking  observations,  and  in  reality,  as  the 
writer  has  come  to  believe,  to  catch  the  scent  of  wheat  or  corn  fields. 
It  is  on  just  such  a  day  as  this  that  Aphodius  served  Say  will  be 
observed  posted  in  precisely  the  same  way,  opening  and  closing  the 
Leaves  of  its  antenna),  evidently  to  catch  the  scent  of  the  fresh  drop- 
pings of  animals.  The  same  movements  characterize  Aphodius  inqui- 
iHitus  Ilbst.  during  the  Indian  summer  days  of  autumn.  The  writer 
has  also  observed  the  plum  curculio,  C  onotrachelus  nenuphar  Hbst., 
acting  in  precisely  the  same  way  in  late  autumn. 

While  discussing  the  subject  of  chinch-bug  migrations,  it  may  be 
best  to  state  here  that  there  is  a  second  flight  of  chinch  bugs  in  sum- 
mer after  the  majority  have  become  fully  developed,  and  not  as  soon 
a-  the  individual  reaches  the  adult  stage,  as  Professor  Sajo  has  found 
to  be  the  case  with  the  European  species,  BUssus  dorice  Ferr.  A 
migration  by  (light  takes  place  in  the  fall,  usually  during  the  period 
of  Indian  summer.  The  magnitude  of  such  migrations  depends  in 
the  spring  on  the  number  of  individuals  that  have  been  in  hiberna- 
tion, and  in  the  summer  and  fall  entirely  on  the  abundance  of  the 
species  during  the  current  year.  If  there  has  been  no  great  abun- 
dance during  the  spring  the  summer  flight  will  not  be  likely  to  attract 
attention.  During  the  invasion  of  1896  in  Ohio  an  individual 
alighted  on  the  writer'-  hand  while  he  was  riding  on  a  street  car  in 
the  heart  of  the  city  of  Columbus.  A  heavy  storm  of  rain  has  much 
influence  in  scattering  the  bug-  in  midsummer,  and  just  preceding  a 
heavy  rain  the  writer  has  noted  the  fully  developed  adults  very 
abundant  on  Indian  corn  plant.-,  while  immediately  after  the  storm 
there  would  be  very  few  to  be  found.  A-  these  storms  were  not 
always  accompanied  by  high  winds,  it  is  probable  that  it  is  the  rain- 
fall that  scatters  the  insects, 


20  THE    CHINCH     BUG. 

In  timothy  meadows  where  the  original  attack  has  begun  along  one 
side  and  gradually  extended  inward,  the  line  of  separation  between 
the  entirely  dead  grass  and  thai  uninjured  is  frequently  not  over  a  yard 

in  width,  and  within  this  narrow,  irregular  strip  we  may  have  the 
dead  and  brow  n.  the  yellowing  indicating  more  or  less  serious  injury, 
and  the  perfectly  healthy  green  of  unattacked  plants.  This  many- 
colored  border  may  change  but  little  in  the  -pace  of  a  week  or  ten 
day-,  excepl  to  advance  wry  materially,  leaving  the  grass  completely 
dead  or  dried  up.  while  the  clover  plants  are  uninjured.  This  indi- 
cates that  the  females,  after  leaving  their  place-  of  hibernation,  do  not 
spread  out  over  any  large  area,  hut  to  a  certain  degree  maintain  their 
gregarious  habits.  The  author  believes  that  these  habits  have  been 
shaped  by  some  past  environment  in  which  the  species  has  been  placed 
for  a  long  period  of  time.  as.  for  illustration,  the  inhabiting  of 
bunches  or  tuft-  of  grass  more  or  less  isolated  from  each  other. 

T<>  what  extent  pairing  takes  place  in  these  places  of  hibernation 
before  the  insects  make  their  way  to  the  cultivated  crop-  i-  a  matter 
of  considerable  uncertainty.  From  his  own  observations  the  writer 
i-  inclined  to  believe  that  only  a  very  insignificant  minority  follow 
t his  course. 

In  his  "  Wanderings  of  Insects  "  Prof.  Karl  Sajo  has  called  atten- 
tion to  the  influence  of  electrical  -tonus  in  the  dispersal  of  insects, 
and  it  is  quite  possible  that  adult  chinch  bugs  may  be  thus  affected  by 
the  heavy  thunder  that  usually  accompanies  these  storms,  during 
which  they  seem  to  disappear  from  corn  plants  on  which  they  had 
previously  congregated. 

OVIPOSITION. 

According  to  most  writers  the  eggs  are  deposited  either  about  ov 
below  the  surface  of  the  ground,  among  the  roots  of  the  grass  or  grain. 
It  i>  nioiv  than  likely  that  the  place  varies  with  the  conditions,  as  the 
eggs  aie  not  infrequently  found  above  ground  about  the  bases  of  the 
plants,  and  even  upon  the  leaves,  though  Ave  have  never  found  them 
there,  but  have  often  found  them  tinder  the  sheath  of  grasses.  It 
would  seem,  then,  that  the  eggs  require  a  cool.  damp,  but  not  a  wet 
local  ion. 

EGG    PERIOD   AND   NUMBER   OF    EGGS   DEPOSITED   BY    EACH    FEMALE. 

Doctor  Shimer  states  that  each  female  deposits  500  eggs,  scattering 
Lhem  over  a  period  of  from  ten  day-  to  three  week-,  and  as  the  adult 
develops  in  fifty-seven  to  sixty  days  after  the  egg-  are  deposited,  or 
about  forty-two  day-  after  hatching,  it  will  be  -ecu  that  some  of  the 
earliest  hatched  young  are  well  along  toward  full  development  by  the 
time  the  last  eggs  are  being  deposited.  According  to  Doctor  Riley, 
the  egg-  hatch,  on  the  average,  in  two  week-. 


DESCRIPTION    ol'    DIFFERENT    STAGES. 


L>l 


In  a  scries  of  breeding-cage  experiments  Prof.  \Y.  ( J.  Johnson  found 
thai  each  female  deposited  from  (.>s  to  237  eggs,  the  egg  period  lasting 
from  eighteen  to  twenty-one  days,  and  the  period  of  oviposition  cover 
ing  from  thirty-eighl  to  forty-two  days.  Forbes  also  record-  in  bis 
Fifth  Report  (p.  II)  experiments  showing  that  the  period  of  incuba- 
tion may  cover  from  twelve  to  twenty-two  days.  (See  Forbes's  L9th 
Report,  pp.  LT7-183.)  It  must  be  remembered,  however,  that  Pro- 
fessor Johnson  had  but  six  females  employed  in  his  experiments  and 
that  these  were  necessarily  under  an  artificial  environment. 

DESCRIPTIONS   OF   THE   DIFFERENT   STAGES   OF   DEVELOPMENT. 


f    the 

Riley's  Seventh  Missouri   Report,  while 


y 

Fig.  2. — Blissus  b  ncupb  rus:  d,  b,  eggs;  c,  newly  Latched 
larva  ;  d,  its  tarsus;  e,  larva  after  first  molt ;  /,  same  after 
second  molt;  g,  pupa;  the  natural  sizes  indicated  at 
sides ;  h,  enlarged  leg  of  perfect  bug  ;  j,  tarsus  of  same, 
still  more  enlarged;  i,  proboscis  or  beak,  enlarged. 
(From  Riley.) 


The  following  descriptions  of  the  egg  and  various  stag< 
young  bugs  are  taken  from 
that  of  the  adult  is  from 
the  original  byThomasSay, 
a-  published  in  his  Ameri- 
can Entomology  (Vol.  I.  p. 
329,  Le  Conte  Ed.)  : 


The  egg. — Average  length  0.03 
Inch,  elongate-oval,  the  diame- 
ter scarcely  g  the  length.  The 
top  squarely  docked  and  sur- 
mounted with  four  small 
rounded  tubercles  near  the  cen- 
ter. Color,  when  newly  laid, 
pale  <>r  whitish,  and  translu- 
cent, acquiring  with  age  an 
amber  color,  and  finally  show- 
ing the  red  parts  of  the  embryo,  and  especially  the  eyes  toward  tubercled  end. 
The  si/.e  increases  somewhat  after  deposition,  and  will  sometimes  reach  near  0.04 
inch  in  length.      (Fig.  2,  a,  b.) 

Larval  stages.— The  newly  hatched  larva  is  pale  yellow,  with  simply  an 
orange  stain  on  the  middle  of  the  three  larger  abdominal  joints.  The  form 
scarcely  differs  from  that  of  the  mature  bug.  being  but  slightly  more  elongate; 
but  the  tarsi  have  but  two  joints  and  the  head  is  relatively  broader  and  more 
rounded,  while  the  joints  of  body  are  snbeqnal,  the  prothoracic  joint  being  but 
slightly  longer  than  any  of  the  rest.  The  red  color  soon  pervades  the  whole 
body,  except  the  first  two  abdominal  joints,  which  remain  yellowish,  and  the 
members,  which  remain  pale. 

After  the  first  molt  the  red  is  quite  brighl  vermilion,  contrasting  strongly 
with  tin'  pale  band  across  the  middle  of  the  body,  the  prothoracic  joint  is 
relatively  longer,  and  the  metathoracic  shorter.  The  head  and  prothorax  ar< 
dusky  and  coriaceous,  and  two  broad  marks  on  mesothorax,  two  smaller  ones  on 
metathorax,  two  on  the  fourth  and  fifth  abdominal  sutures,  and  one  at  tip  of 
abdomen  are  generally  visible,  but  sometimes  obsolete:  the  third  and  fourth 
joints  of  antennae  are  dusky,  but  the  legs  still  pale.  After  the  second  molt  the 
head  and  thorax  are  quite  dusk-  ,,id  the  abdomen  duller  red,  bu1  the  pale  trans- 
verse band  is  still  distinct;  the  wing  pads  become  apparent,  the  members  are 
more  dusky,  there  is  a  dark-red  shade  on  the  fourth  and  fifth  abdominal  joints. 


)■) 


THE    CHINCH    BUG. 


and,  centrally,  a  distind  circular  dusky  spot,  covering  the  last  three  joints. 
i  Fig.  2,  0,  >i.  • .  /'.  i 

Tin  pupa,  in  Hit-  pupa  all  the  coriaceous  parts  are  brown-Mack,  the  wiii!;- 
pads  extend  almost  across  the  two  pale  abdominal  joints  which  are  now  more 
dingy,  while  the  general  color  of  the  abdomen  is  dingy  gray;  the  body  above 
Is  -lightly  pubescent,  the  members  are  colored  as  in  the  mature  )»uur.  the 
three-jointed  tarsus  is  foreshadowed,  and  the  dark  horny  spots  at  tip  of  abdo- 
men, both  above  and  in-low.  are  larger.     (Fig.  2,  g.) 

'I  li<  adutt.— Blackish,  hemelytra  white  with  a  black  spot 

Inhabits  Virginia. 

Body  Ion-,  blackish,  with  numerous  hairs.  Antenna?,  rather  short  hairs; 
second  joint  yellowish,  longer  than  the  third:  ultimate  joint  rather  longer 
than  the  second,  thickest;  thorax  tinged  with  cinereous  before,  with  the  basal 
edge  piceous;  hemelytra  white,  with  a  blackish  oval  spot  on  the  lateral  middle; 
rostrum  and  feel   honey-yellow;  thighs  a  little  dilated. 

Length   less  than  three-twentieths  of  an  inch. 

I  took  a  single  specimen  on  the  Eastern  Shore  of  Virginia. 

Tli.-  whiteness  «»t'  the  hemelytra.  in  which  is  a  blackish  spot  strongly  con- 
trasted, distinguishes  this  species  readily. 

To  i he  foregoing  description  of  the  adult  Dr.  Asa  Fitch,  in  his 
second  reporl  on  the  In-ects  of  Xew  York,  adds  brief  descriptions  of 

nine  varieties,  all,  with  bnt  one  exception, 
being  based  upon  slight  variation-  in  color, 
some,  perhaps,  being  due  to  immaturity,  the 
single  exception  being  the  short- winged  in- 
land form,  of  which  variations  from  the 
nearly  wingless  to  fully  winged  are  shown 
in  figures  3  and  4. 

Leaving,  then,  out  of  consideration  the 
color  varieties  as  arranged  by  Doctor  Fitch. 
we  have  a  long-winged  form  (fig.  3)  in 
which  individuals  from  the  eastern  portion 
of  the  country  differ  from  those  found  in  the 
West  by  being  more  hairy  and  robust,  as 
pointed  otit  by  Mr.  Van  Duzee,  and  a  short- 
winged  form  (fig.  d).  found  along  the  seacoast,  ami  in  the  North 
Atlantic  ( !oas1  region,  extending  inland  a-  far  a-  the  country  adjacent 
to  the  ( iivai  Lakes. 


Fig.  3. — Blissus leucopterus:  adult 
of  long-winged  form.  Much 
enlarged  (original). 


DEVELOPMENT  AND  HABITS   OF   THE   YOUNG. 

The  newly  hatched  young  are  very  active,  and  the  first  to  appear 
may  be  observed  with  their  progenitors  about  the  bases  of  wheat,  corn, 
or  grass  plants,  and  later  all  stages  are  -ecu  mingling  together,  having 
little  appearance  of  belonging  to  the  same  species,  so  greatly  do  they 
vary  in  size  and  color  in  their  severa]  stages  of  development. 

A-  a  nde  the  bugs  confine  themselves  to  the  lower  portion  of  the 
plant-  attacked,  but  may  later  push  their  way  upward, especially  ifthe 
lower  portion  become-  tough  and  woody, finally  covering  the  plant- in 


DEVELOPMENT    \Nl>    HABITS    OF    THE    Y<U'N< 


23 


patches,  as  seen  in  figure  5,  where  they  are  shown  on  a  stalk  of  young 
corn.  Mr.  E.  A.  Schwarz  relates  a  curious  exception  to  this  habit  in 
Florida  upon  sand  oats,  Uniola  paniculata^  where  the  entire  develop- 
ment of  the  insect  is  undergone  upon  the  highest  part  of  this  tail 
plant  and  not  close  to  the  bottom.  Mr.  Schwarz  lias  given  as  a  proba- 
ble reason  for  this  the  Tact  that  strong  winds  arc  continually  blowing 
the  fine,  sharp  sand  through  among  the  lower  parts  of  the  plants, 
rendering  it  nearly  or  quite  impossible  for  the  bugs  to  remain  in  thai 
situation,  thus  forcing  them  to  seek  their  sustenance  farther  up  the 
plants.  While  figure  5  gives  a  good  representation  of  the  appearance 
of  a  corn  plant  when  the  chinch  bugs  are  present  in  excessive  numbers. 
yet  the  writer  has  invariably  found  that  these  bugs  much  prefer  a 
stalk  that  has  been  blown  down  by  the  wind  or  partly  broken  off  by 
the  plow  and  Left  lying  nearly  Hat  upon  the  ground. 

In  timothy  meadows  the  very  young  are  to  be  found  only  by  pull- 
ing away  the  soil  from  about  the  bulbous  roots  and  drawing  down 


Fig.  4. — BUssus  leucopterus:  adults  of  short-winged  form.     Much   enlarged    (original). 

the  dead  sheaths  that  usually  envelop  them.  An  observer  may  even 
pull  up  a  tuft  of  i:ra—  entire,  and  yet,  unless  he  examines  in  this  way 
closely,  may  overlook  them,  so  snugly  are  they  thus  ensconced  among 
the  roots.  If  driven  to  forsake  a  tuft  of  grass  the  young  bugs  move  to 
another  and  crawl  downward,  and  are  soon  to  be  found  as  snugly 
settled  as  before.  It  is  onty  when  they  are  older  and  well  advanced 
toward  maturity  that  they  work  to  any  extent  above  ground,  and 
e\cn  then  only  in  cases  where  they  are  present  in  great  number--. 
Singularly  enough,  where  infested  meadows  are  plowed  up  and 
planted  with  corn  the  females  seem  to  ignore  the  young  corn  plants 
and  select  the  occasional  -tray  clumps  of  timothy  that  cultivation  has 
failed  to  destroy  and  deposit  their  v<xii>  about  these,  so  that  Later  the 
young  may  be  swarming  afco  I  these  Last,  while  hardly  one  is  to  be 
found  about  the  young  corn.  This  is  precisely  the  opposite  of  what 
is  observed  farther  west. 


lM  the  chinch  bug. 

Although  living  externally  on  their  food  plants,  and  notwithstand- 
ing the  fad  that  the  young  may  attack  the  bases  or  eveu  the  roots  of 
some  of  these,  the  species  is  essentially  an  external  feeder,  and  appears 
while  thus  engaged  almost  totally  indifferent  t<>  possible  attack-  of 
natural  enemies.  When  not  feeding,  however,  there  is  at  times  a 
tendency  to  hide  away  under  the  sheaths  of  young  corn  or  beneath 
clod-  of  earth  or  bunches  of  coarse  stable  manure,  where  this  has 
been  recently  applied  and  left  more  or  less  exposed  on  the  surface  of 
the  ground.  The  writer  has  noted  this  in  cases  where  neither  an 
uncomfortable  temperature  nor  wet   weather  necessitated  protection. 

A-  has  been  shown  in  the  description  of  the  larval  stages,  there  are 
four  molt-  between  the  egg  and  the  adult  state.  Just  how  the  niolt- 
ing  larvae  act  we  have  never  been  able  to  determine:  neither  have  we 
witnessed  pupation,  but  a  fully  developed  pupa  that  is  ready  to  molt 
is  easily  distinguished  by  it-  larger  size  and  more  tightly  fitting  skin, 
which  i-  almost  shining  white  on  the  median  ventral  surface  of  the 
abdomen.  It  now  hides  itself  away,  seemingly  preferring  to  gel 
under  the  -heaths  of  grasses  or  grains;  hut  if  these  are  not  con- 
venient it  will  crawl  under  loose  clods,  or  even  into  crevices  in  the 
ground.  While  thus  hidden  away  the  pupa  skin  split-  along  the 
hack  and  the  fully  developed  adult  make-  it-  way  ottt.  leaving  the 
empty  -kin  behind.  These  last  are  very  frequently  mistaken  for 
dead  chinch  bugs,  and,  when  moldy,  the  farmer  i-  very  likely  to  sup- 
pose that  they  are  bugs  which  have  been  killed  by  the  fungus  Sporo- 
trichum  globulift  rum,  if  this  has  been  applied  in  the  fields. 

On  hi -i  emerging  from  the  pupa  the  adtdt  is  generally  of  a  dull 
pink  color,  except  the  wings,  which  are  white,  exclusive  of  the  veins: 
these  being  of  the  same  pinkish  hue  as  the  body.  In  a  short  time 
these  colors  change  to  the  normal  ones  of  the  species,  but  during  the 
breeding  season  these  newly  developed  adults  may  be  observed  crawl- 
ing about  with  the  young  of  all  stage-  as  well  as  the  maturely  colored 
adult-. 

If  this  development  has  been  taking  place  in  a  wheat  held  and  the 
grain  i-  harvested  at  this  time,  or  if  from  any  other  cause  the  food 
supply  becomes  suddenly  exhausted,  all  sizes  of  larvae  with  pupae  and 
adult-  will  -tart  oil'  on  foot  to  hunt  for  a  fresh  supply.  Though 
many  individuals  may  now  have  become  fully  developed,  and.  so  far 
a-  can  be  determined,  possess  wing-  entirely  fitted  for  active  service, 
nevertheless  they  will  crawl  along  a  dusty  road  or  aero--  freshly 
plowed  fields  in  company  with  their  less  fortunate  fellow.-,  seemingly 
never  for  a  moment  supposing  that  they  can  -pan  the  intervening 
space  by  (light.  The  writer  i-  totally  unable  to  account  for  this  phe- 
nomenon in  the  specie-  at  thi-  time,  the  disinclination  to  use  the  wings 
being  so  wholly  unlike  the  habit-  of  B.  dorice,  a-  shown  by  the  careful 
and  painstaking  observations  of  Professor  Sajo  in  Hungary.    Again. 


NUMBER    OF    GENERATIONS    ANNUALLY.  25 

the  seeming  desire  on  the  pari  of  the  pupae  to  secrete  themselves  \\  bile 
transforming  to  adults  does  not  at  all  coincide  with  the  idea  of  a 
supposed  immunity  from  attacks  of  natural  enemies.  Surely  our 
species  of  Blissus  has  not  always  lived  where  natural  enemies  were  as 

few  as  they  are  with  us  at  the  present  time.  Even  where  we  have 
both  the  long-winged  and  short-winged  forms  occurring  together  in 

timothy  meadows  there  is  no  such  haste  exhibited  on  the  part  of  the 
former  to  escape  from  the  companionship  of  the  latter,  as  observed 
by  Professor  Sajo.  We  know,  however,  that  our  specie-  certainly 
does  enjoy  a  considerable  immunity  from  natural  enemies,  though  its 
conspicuous  colors  in  both  the  larva]  and  adult  stages  contrast  very 
strongly  with  those  of  its  usual  food  plants  and  its  presence  is  still 
further  advertised  by  its  strangely  persistent  gregarious  habits.  We 
have  come  to  suppose  the  species  to  be,  in  part  at  least,  protected 
from  attack  by  its  vile  odor,  and  so,  indeed,  it  may  be  in  the  United 
States,  but  the  writer  fully  believes  that  somewhere  in  its  southern 
habitat  it  will  be  found  to  have  one  or  more  enemies,  like  the  ant. 
Eciton  Iki  unit a  in  Fab.,  of  Central  America,  for  illustration.  Our 
native  ants,  however,  will  seldom  attack  even  the  young. 

NUMBER    OF    GENERATIONS    ANNUALLY. 

Over  the  most  of  its  area  of  habitation  in  North  America,  at  least, 
the  chinch  bug  is  two  brooded,  though  in  northeastern  Ohio  the 
writer  has  totally  failed  to  detect  the  second  brood,  or,  in  fact,  to 
perceive  any  indications  that  a  second  brood  occurs;  but  this  will  be 
referred  to  later.  As  previously  shown,  there  is  not  sufficient  proof 
at  hand  to  warrant  the  statement  that  there  is,  even  in  the  far  South. 
a  partial  third  brood.  It  is  probable  that  the  number  of  broods  of 
this  species  annually  has  been  primarily  decided  in  its  home  in  the 
tropical  regions  by  the  wet  and  dry  seasons  occurring  there,  and  that 
we  have  in  the  North  these  same  broods  occurring  at  slightly  differ- 
ent periods  under  the  influence  of  a  change  from  wet  and  dry  to  hot 
and  cold  -easons. 

Belt,  in  his  Naturalist  in  Nicaragua,  has  the  following  to  say  with 
regard  to  the  seasons  on  the  northeastern  side  of  that  country:  "  'The 
rains  set  in  in  May  and  continue  with  occasional  intermissions  until 
the  following  January,  when  the  dry  season  of  a  little  more  than  three 
months  begin-*'  (p.  103).  ''The  heaviest  rains  fall  in  July  and 
August,  and  at  those  times  the  brooks  are  greatly  swollen."  "In 
September,  October,  and  November  there  are  breaks  of  fine  weather, 
sometimes  lasting  for  a  fortnight,  but  December  is  generally  a  very 
wet  month,  the  rains  extending  far  into  January.  SO  that  it  is  not 
until  February  thai  the  roads  begin  to  dry  up"  (p.  L04).  It  seems 
that  possibly  we  have  \\rw>  the  key  to  the  secrel  of  the  number  of 


26  THK    CHINCH    BUG. 

broods  annually  of  the  chinch  bug.  That  this  insect  may  be  able  to 
adapi  itself  still  further  to  changed  latitude  and  environments  and 
become  single  brooded  is  not  at  all  impossible.     As  illustrating  the 

ease  with  which  insects,  at  Leasl  some  of  them,  can  change  their 
habits  to  correspond  with  their  environment,  we  have  in  South  Aus- 
tralia the  following  fact-  regarding  the  codling  moth.  ( farpoca psa 
pomonella  L.,  of  which,  though  being  -till  double  brooded,  "the 
winter  caterpillars  hatch  into  moth-  irregularly  from  the  beginning 
of  October  until  the  middle  of  November  and  deposit  their  eggs 
accordingly,  giving  rise  to  a  succession  of  young  caterpillar-  until 
the  beginning  of  December.  About  the  third  week  in  December  the 
firsl  moth-  of  the  second  brood  begin  to  appear  and  deposit  coo-,  and 
members  of  this  second  generation  of  moth-  continue  hatching  and 
effg  la  vino-  until  the  end  of  February."0 

The  author'-  note-  on  the  chinch  bug  in  northeastern  Ohio  are 
as  follow-:  Very  young  Larvae,  with  what  appeared  to  be  their  pro- 
genitor-, were  observed  at  Jefferson,  Ashtabula  County,  within  11 
mile-  of  the  shores  of  Lake  Erie,  June  16,  1803.  there  being  no 
advanced  larva1  among  them.  On  August  27,  1896,  a  few  miles 
south,  at  West  Andover,  in  the  same  county,  only  adult-  were 
observed  in  two  days'  search,  though  some  of  these  showed  by  their 
color  that  they  had  but  recently  passed  the  pupal  stage.  In  this 
latter  locality.  May  7.  1897.  the  sexes  were  pairing,  but  no  young 
were  present  so  far  as  could  be  observed,  while  to  the  south  and  we-t 
of  this  locality.  June  8  and  9,  precisely  the  same  condition-  obtained 
as  to  the  bugs,  no  young  appearing  at  this  time.  Quite  copious  rain- 
might  have  destroyed  the  young,  but  within  15  miles  of  these  locali- 
ties,  on-  July  14  of  this  year,  larvae  were  found  after  first  molt  and 
stages  intervening  between  these  and  the  adults.  Near  Youmr-town. 
on  October  3,  1897,  only  adult-  were  present,  pairing  was  not  in  prog- 
ress, and  the  insect  w  a-  not  pairing  in  Ashtabula  County  on  August 
l;7.  L896.  June  9,  1808,  only  two  very  voting  larvae  could  be  found 
at   Salem,  about    15  mile-  southwest  of  Youngstown. 

[Jp  to  October  17.  1898,  no  young  of  a  second  brood  had  been 
observed,  though  careful  search  had  been  made  from  time  to  time  in 
the  fields  and  meadows  of  northeastern  Ohio,  and  a  large  number  of 
adult-  which  developed  in  July  and  August,  and  since  kept  in  con- 
finement, had  not  only  not  reproduced,  but  had  shown  no  disposition 
whatever  to  pair.  On  the  other  hand,  in  southwestern  Ohio,  in  the 
vicinity  of  Cincinnati,  on  September  24,  where  the  species  occurred 
in  abundance,  fully  7.~>  per  cent  were  pupa1,  the  remainder  being  made 
up  of  larva?,  some  id'  them  quite  young,  and  adults  in  about   equal 


rge  Quinn,  in  Journal  of  Agriculture  and  Industry.  South  Australia,  Vol. 

I.  p.  112. 


.\r.Mi;i.i;    OF    GENERATIONS    ANNUALLY.  27 

proportions,  some  of  the  latter  showing  by  their  immature  color- 
that  they  had  but  just  passed  the  pupal  stage. 

Hatching  is  not  fully  in  progress  in  the  Northeast  before  the  25th 
of  June,  only  an  occasional  individual  having  passed  the  first  moll 
before  the  LOth  of  July.  In  the  Light  of  the  information  that  has 
been  gained  by  these  observations,  the  occurrence  of  a  second  brood 
bf  young  in  northeastern  Ohio  is  doubtful. 

The  late  \h\  J.  A.  Lintner,  in  his  studies  of  the  outbreak  of  this 
insect  in  New  York  State  in  L882  and  L883,  seems  to  have  relied 
much  on  the  published  habits  of  tie1  species  farther  west — as,  indeed. 
the  writer  has  himself  done  until  recently  and  made  no  exact 
Studies  of  the  species  at  that  time;  and  in  his  annual  report,  where 
the  outbreak  is  discussed,  no  absolute  proof  of  the  existence  of  a  sec 
pnd  brood  in  New  York  is  presented.0  The  occurrence  of  a  second 
brood  of  young  in  northern  Illinois,  as  indicated  by  Doctor  Fitch, 
has  always  been  considered  as  settled,  and  in  a  more  northern  lati- 
tude than  northern  Ohio,  so  that  there  must  be  some  other  influences 
besides  latitude  to  account  for  the  phenomenon.  That  the  species 
has  occupied  this  territory  for  many  years  is  indicated  by  the  obser- 
vations of  Mr.  E.  P.  Van  Duzee,  of  Buffalo,  N.  Y.,  who  wrote  that 
the  insect  was  as  abundant  twenty-three  years  ago  as  at  the  present 
time,  so  that  whatever  effect  on  the  insect  the  recent  occupation  of 
the  country  might  have  had,  that  effect  has  passed  away  and  a  con- 
dition of  what  we  might  call  equilibrium  now  exists  here. 

On  July  T.  1889.  in  the  extreme  northern  part  of  Indiana,  the 
writer  found  an  abundance  of  young  which  had  not  yet  molted  for 
the  first  time.  Dr.  A.  S.  Packard  record-  adults  as  pairing  at  Salem, 
Mass.,  June  17,  1871,  as  quoted  by  Doctor  Lintner,  while  the  latter 
gentleman*  records  the  }Toung  as  occurring  in  Lawrence  County. 
X.  Y..  about  June  .">.  1883. 

Hardly  have  the  latest  hatched  young  of  the  first  brood  developed 
to  the  adult  before  the  young  of  the  second  brood  begin  to  appear. 
In  southern  Ohio  this  is  about  the  first  week  in  August,  Genera  11  v 
these  young  do  little  injury,  because  the  wheat  has  long  since  been 
harvested  and  the  corn  is  usually  too  far  advanced  and  tough  to 
offer  a  desirable  source  of  food  supply,  except  in  cases  where  fields 
have  been  planted  very  late,  and  here  the  write]'  has  known  them  to 
work  considerable  injury,  especially  in  seasons  of  severe  drought  that 
prevented  the  rapid  growth  of  the  plants.  Fall  attacks  on  wheat  are 
rare,  and  the  injury  i-  never  of  a  serious  nature,  a-  i(  i-  usually  the 
Case  that  by  the  time  the  young  wheat  is  large  enough  to  invite  attack 
the  chinch  bug-  are  searching  for  winter  quarters. 

-..Mini  Report  State  Km ologist  of  New  York,  pp.   L48-164,   L885. 

>'  Loc.  cit.,  pp.  L58,   159,  104. 


28  THE    CHINCH    BUG. 


In  the  timothy  meadow-  of  northern  and  northeastern  Ohio,  how- 
.  \<t.  the  principal  injury  is  done  during  August  and  September,  and  1 
in  favorable  weather  on  into  October.  Now.  if  we  allow  sixty  days 
for  development  from  the  egg,  it  would  be  September  before  the  ap- 
pearance of  the  adult-  of  the  brood  to  which  these  various  young 
belonged.  II'  all  eggs  were  deposited  immediately,  it  would  he 
November  before  the  adult-  of  the  second  brood  would  begin  to 
occur,  a  condition  of  a  Hair-  that  ha-  never  been  observed.  As  pre- 
vously  -low  11  in  this  bulletin,  the  fir-t  brood  is  fully  developed  in 
northeastern  Ohio  by  the  first  Of  September,  hut  there  certainly  is 
no  indication  that  a  second  brood  of  young  is  developed  during  Sep- 
ieinher  and  October.  It  would  seem,  then,  that  from  northern  Ohio 
through  New  York.  New  England,  and  probably  to  Nova  Scotia 
the  adult-  from  the  first  brood  of  Larvae  winter  over,  and  that  there  is 
here  but  one  annual  brood. 

DESTRUCTIVENESS  LARGELY  DUE  TO  GREGARIOUS  HABITS. 

Attention  has  been  directed  previously  to  the  gregarious  habits 
of  the  chinch  bug,  and  Ave  only  refer  to  the  phenomenon  again  be- 
cause it  i-  to  this  that  it-  destrnctiveness  is  largely  due.  It  i>  not 
the  excessive  number-,  but  the  persistency  with  which  they  will 
congregate  en  masse  on  limited  areas,  that  renders  their  attacks 
-o  fruitful  of  injury.  With  an  ample  supply  of  food  the  young 
develop  and  leisurely  diffuse  themselves  over  the  adjacent  fields, 
and  there  are  neither  swarming  nights  nor  migrations.  In  1884, 
in  northern  Indiana,  a  small  field  of  wheat  was  severely  attacked 
by  chinch  bugs.  At  harvest  there  was  every  prospect  of  a  migration 
from  the  field  of  wheat  to  an  adjacent  one  of  corn,  and  the  bug-  were 
present  in  sufficient  numbers  to  have  worked  serious  injury  to  the 
latter:  but  the  Avheat  had  grown  tip  thinly  on  the  ground,  and  there 
had  sprung  up  among  the  grain  a  great  deal  of  meadow  foxtail  grass, 
Ixophorus  (Setaria)  glaucus,  and  panic  grass,  Panicum  crus-galli, 
and  to  these  grasses  the  bug-  transferred  their  attention,  finishing 
their  development  thereon,  and  later,  so  far  a-  could  be  determined, 
they  scattered  by  flight  out  over  the  adjacent  fields,  working  no  fur- 
ther injury.  Pedestrian  migrations  may  continue  for  a  fourth  of  a 
mile  or  even  more,  but  on  reaching  a  suitable  food  supply  the  tend- 
ency of  the  bugs  i>  t<»  congregate  upon  their  food  plant-  until  these 
are  literally  covered  with  individuals  varying  in  color  from  the 
black'  and  white  of  the  adults  to  the  bright  vermilion  of  the  more 
advanced  larvse.  (See  fig.  5.)  Whatever  tendency  there  i-  ex- 
hibited toward  a  wider  diffusion  is  confined  to  the  adult-,  the  others 
remaining  and  leaving  in  a  body  only  when  the  plant  on  which 
they  have  congregated  ha-  been  drained  of  it-  juice-  and  ha-  begun 


I  OOD    PLANTS.  29 

to  wither,  when  they  simply  crawl  to  1 1  u*  nearest  plants  and  again 
congregate  upon  these  as  before.  In  case  the  migration  has  been 
to  a  held  of  corn,  if  this  is  badly  overgrown  with  either  of  the  two 
grasses  previously  named,  the  bugs  will  collect  upon  the  latter,  and 
unless  the  corn  plant-  are  very  small  they  will  not  as  a  rule  attack 
them  until  the  grass  has  been  killed.  Some  farmers  have  gone  so 
far  a-  io  claim  thai  a  benefit  is  derived  from  a  certain  abundance 
of  chinch  bugs,  the  statement  being  made  that  the  bugs  will  kill 
out  these  grasses  to  an  extent  that  nothing  else  will.  It  is  clear 
that  the  acquisition  of  wings  is  not  the  signal  for  the  adults  to 
abandon  the  companionship  of  the  larvse  ami  pupae,  yet  they  do 
gradually  disappear  from  among  them.  It  is  possible  that  the 
disposition  to  pair  does  not  exist  until  the  individual  has  reached 
a  certain  age  beyond  seeming  maturity,  and  that  it  is  not  until  the 
passion  for  mating  has  overcome  their  gregarious  inclination  that 
they  are  disposed  to  migrate.  Or  it  may  be  that  the  phenomenon 
may  l»e  explained  on  the  supposition  that  when  the  pairing  season 
approaches  the  males  scatter  out  in  order  to  find  females  with  which 
they  are  not  akin,  thus  following  oirt  natural  selection  and  prevent- 
ing a  continual  interbreeding.  Over  the  northern  United  States, 
at  Least,  tin1  injury  in  cultivated  fields  is  done  almost  entirely  by  the 
young  bugs,  but  in  the  timothy  meadows  the  damage  is  due  as  much, 
if  not  more,  to  the  depredations  of  the  adults. 

FOOD  PLANTS. 

As  to  food  plants,  there  can  be  no  doubt  that  these  consisted  origi- 
nally of  the  native  grasses.  This  is  amply  proved  by  the  observa- 
tions of  Fitch  and  Le  Baron,  in  Illinois;  Dr.  J.  C.  Neal,  in  Florida 
and  Oklahoma:  Marlatt.  in  Kansas;  Schwarz,  in  Florida;  and  by 
those  of  Mr.  Henry  O.  Hubbard  in  the  midst  of  the  Colorado  desert 
in  California.  Regarding  this  last  statement,  Mr.  E.  A.  Schwarz 
wrote  as  follows : 

Yon  may  be  interested  i<>  learn  that  chinch  bugs  were  collected  this  year 
(1897)  on  March  28  by  Mr.  II.  G.  Hubbard,  at  Salton,  in  the  midst  of  the 
Colorado  deserl  of  <  !alifornia.  This  locality  is  considerably  below  the  ocean  level, 
;iik1  represents  an  ancient  extension  of  the  Gulf  of  California.  Even  .-u  the 
presenl  time  the  Salton  Basin  is  occasionally  flooded,  the  water  entering  through 
New  River,  which  runs  from  the  mouth  of  the  Colorado  River  into  the  s.-ilton 
Basin.  The  specimens  were  taken  on  ;i  species  of  coarse  :rr;is^  which  is 
Incrusted  wit  h  ;i   saline  deposit. 

No  wonder  that  the  chinch  bug  is  accused  of  being  a  seashore 
species ! 

Of  cultivated  grassesfor  such  as  occur  in  cultivated  fields,  probably 
Ixophorus  glaucu8  and  Panicum  crus-galli  are  the  favorites,  though 
millet  and  Hungarian  grass  are  apparently  nearly  as  attractive.     As 


30 


THE    C1I1XCI1    BUG. 


early  as   lsl">.  in   Illinois,  Dr.  William  Le  Baron,  afterward-  State 
entomologist,  gave  the   food   plant-  of  the  chinch  bug  as  follows: 


Fig.  5.     Corn  plant   two  feel   tall  infested  with  chinch  bugs.      (Author's  Illustration.) 

"all   kinds  of  grain,  corn,  and   herd's-grass "    (timothy).0 
But  t<>  tlii-  dav  in  [llinois,  a-  shown  by  the  observations  of  Professor 

Prairie  Farmer,   I  »ecember,   L845, 


cnsects  mistaken   fob  chinch   bugs. 


31 


Forbes  ami  the  writer,  the  species  will  attack  timothy  only  in  cases 
where  it  is  compelled  to  do  so  by  reason  <>f  a  lack  of  other  food.  In 
addition  to  the  preceding,  Doctor  I  low  aid  gives  broom  corn,  sorghum, 
chicken  corn,  Bermuda  grass  (( ?apriola  dactylon),  bluegrass  (/'<></ 
pratenshs),  crab  grass  (Synthei-isma  sanguinalis) ,  and  bottle  grass 
(Ixophonis  ririd'/s).  and  also  states  that  in  the  rice  fields  near 
Savannah,  Ga.,  in  August,  L881,  he  observed  the  winged  adults  upon 
the  heads.  Prof.  II.  A.  Morgan  wrote  that  in  1M>7  it  had  become  a 
serious  enemy  to  "  E*rovidence  "  rice  in  Louisiana,  where  fortwo  years 
it  had  seriously  injured  corn,  and  the  writer  was  informed  through 
other  sources  that  it  proved  injurious  to  corn  again  in  L898.  Adults 
have  often  been  found  collected  in  the  silk  of  belated  ears  of  corn  in  the 
fields  in  September,  when  all  other  parts  of  the  plant  had  either  become 
too  old  and  tough  to  afford  nourishment  or  else  had  been  killed  by  the 
frosts  of  autumn.  Prof.  Lawrence  Bruner  lias  recorded  the  insect  as 
feeding  upon  so-called  wild  buckwheat  (Polygonum  dumetorum  or  P. 
con v 61 villus).0  The  writer  has  never  seen 
chinch  bugs  attack  bluegrass  (Poa  pra- 
tensis))  and  has  seldom  witnessed  them  in- 
juring oats,  hut  on  September  27,  1904,  he 
observed  larvae,  pupa1,  and  adults,  the  last 
all  fully  winged,  attacking  Arrhenatherum 
(oat  grass)  on  the  experiment  farm  of  the 
University  of  Tennessee,  at  Knoxville. 
Over  the  western  country  the  major  por-     FlG-  6.-ity«*u«  angustatus:  b >,pu 

.''.'./•  c,  mature  bug.     (From  Riley.) 

tion  or  the  damage  done  is  to  nelas  or 
wheat,  barley,  rye.  and  corn,  the  outbreak  generally  originating  in 
wheat  or  barley  fields  and  the  bugs  migrating  at  harvest  to  the  corn- 
fields. (See  fig.  .">.)  In  the  eastern  part  of  the  country,  where  the 
timothy  meadows  are  the  most  seriously  infested,  this  is  not  the  case, 
and  here  the  migrations  are  as  likely  to  be  to  the  timothy  meadows  as 
to  the  field-  of  corn,  where  both  are  equally  within  reach.  Besides, 
everything  indicates  that  a  very  large  proportion  of  the  adults  may 
hibernate  in  these  meadows,  even  making  their  way  thereto  in  the 
autumn. 


pa; 


INSECTS  THAT  ARE  MISTAKEN  FOR  CHINCH  BUGS. 


Messrs.  Osborn  and  Mally6  have  given  a  list  of  twelve  species  of 
Hemiptera  which  have  been  mistaken  with  more  or  less  frequency  for 
the  chinch  bug,  the  li-t   being  a-   follow-: 

Nysim  angustatus  Uhl.,  the  false  chinch  bug  (fig.  0).  is  probably 
the  rnosi    frequently  mistaken    for  the  true  chinch  bug,  as  it   often 

a  Report  Commissioner  of  Agriculture,  1887,  pp.  57  58. 
&Bul.  No.  :\'2.  inw.-i  Alt.  College  Exp.  Sta.,  pp.  :,.<;:>.  385, 


THE    CHIN ('II    BUG. 


F  i  < ; .    I.—Piesma    tin 
erea.   (From  Riley.  I 


breeds  in  considerable  numbers  under  purslane,  amaranth,  etc.,  and 
more  than  any  other  insect  resembles  the  chinch  bug.  It  is,  however. 
of  a  light-gray  color,  which  will  always  distinguish  it  from  its  more 
destructive  fellow. 

Ischnodi  in  us  falicus  Say.  or  the  long  chinch  bug,  as  it  is  sometimes 
called,  is  much  lamer  and  longer  than  the  true  chinch  bug. 

I schnorhynchus  didymus  Zctt.  is  more  robust,  of 
a  light-tawny  color,  with  prominent,  glassy  wings. 
Peliopelta  abbreviata  Uhl.  is,  next  to  the  false 
chinch  bug,  probably  the  most  often  mistaken  for 
the  true  insect,  and  especially  is  this  true  in  local- 
ities wIktc  the  brachypterous  form  of  Blissus 
leucopterus  al^unds,  viz.  in  timothy  meadow-.  Its 
broader  head  and  body,  however,  quickly  enables 
one  to  distinguish  it. 

Geocoris  fuliginosus  Say,  G.  borealis  Dallas,  G. 
bullatus  Say.  and  G.  limbatus  Stal,  according  to 
( )sborn  and  Mally,  have  all  been  confused  with  the 
chinch  bug  in  Iowa.  These  are  all  broader  and  flatter  than  the  true 
chinch  bug.  the  head  being  nearly  as  wide  as  the  thorax. 

Ligyrocoris  sylvestris  L.  is  larger  than  the  true  chinch  bug,  and 
it-  wing-  are  quite  dark  instead  of  white. 

Trapezonotus  nebnlosus  Fall,  is  a  trifle  larger  and  its  body  is  not 
so  black  as  in  the  chinch  bug. 

Cymodema  tabida  Spin,  is  longer  than  the  true  chinch  bug.  of  a 
light  brown  color,  and  the  ends  of  the  wings  are  glas-y. 

I'ri />Jtl<  /as-  insidicsus  Say.  or  the  insidious  flower  bug  (fig.  15).  as 
it  is  more  commonly  called,  is  another  bogus  chinch  bug.  though  an 
enemy  of  the  true  pest,  as  previously  stated. 

Piesma  cinerea  Say.  the  ash-gray  leaf  bug   (fig.  7).  is  often  mis- 
taken  for  the  true  chinch  bug.  though  its  form 
differs  greatly  from  that  of  the  latter.     It  is  often 
quite     abundant,     but     not     in     grain     fields     or 
meadows. 

Corimelcena  pulicaria  Germ.,  the  flealike  negro 
bug  (fig.  8),  ha-  been  confused  with  the  chinch 
bug:  though  it  doe-  not  in  the  least  resemble  the 
latter,  either  in  form  or  color,  and  it-  confusion  is 
probably  to  be  accounted  for  by  the  fact  of  its  being  occasionally 
Pound  in  wheat  fields  in  considerable  numbers. 

Braehyrliynclms  granidatus  Say  (fig.  9)  has  been  mistaken  for 
the  chinch  bug  in  Ohio,  and  in  a  way  that  was  somewhat  amusing. 
Farmers  in  southern  Ohio,  during  the  winter  of  L896-97,  were  burn- 
ing over  the  woodland-  with  a  view  to  destroying  the  hibernating 
insects,  when  there  came  several  discouraging  reports  to  the  effect 
that  such  a  course  would  be  ineffective,  a-  the  bugs  were  wintering 


Fig.  8. — Corimelcena  )»"li- 
caria.     (From  Riley.) 


LOSSES    CAUSED    r.Y    CIII.Xcn    BUGS. 


33 


in  the  tops  of  trees,  especially  where  the  tops  were  dead,  under  the 
bark  and  often  from  50  to  75  Peel  from  the  ground.  This  was  a 
piece  of  astounding  information,  to  the  writer  at  Least,  and  it  was 
onlv  after  securing  specimens  that  he  was  able  to  solve  the  mystery. 
This  insect,  in  all  stages  of  development  except  the  egg^  hibernates 
under  loose  bark.  It  i-  broader  and  much  Hatter  than  the  true  chinch 
bug,  l>nt  the  w  ilia's  are  white  and  the  body  black. 

The  object  in  calling  attention  to  these  bogus  chinch  bugs  is  to 
prevent  their  confusion  with  the  true  Blissus  leucopterus,  a-  in  some 
cases  people  finding  them  and  supposing  them  to  he  the  true  pot 
are  likely  to  become  panic  stricken  and  often  destroy  property  un- 
Qecessarily,  so  notorious  has  the  name  "chinch  bug"  become  in  the 
United  States. 

LOSSES   CAUSED  BY  CHINCH  BUGS. 


It   would  appear  that   this  pest    first   made  its  presence  known  by 
its  ravages  in  the  wheat   iields  of 
Carolina   fanner-:   for  we  are  told 
L785   the  Iields  in    this  State   were 
with  them  as  to 


the  Xort h 
that  "in 
so    overrun 

threaten  a 
of  the  grain. 
the  crops 


total  destruction 

And  at  length 
w  e  r  e  s  o  d  e  - 
stroyed  in  some 
districts  that 
farmers  were 
obliged  to 
a  b  a  n  d  on  t  h  e 
Sowing  of  wheat. 
It  was  four  or 
five  years  that 
they  continued 
SO  numerous  at  this  time."  " 

In  the  year  L809,  a-  stated  by  Mr.  J.  W.  Jefferys,''  the  chinch  bug 
again  became  destructive  in  North  Carolina  to  such  an  extent  that 
in  Orange  County  farmers  were  obliged  to  suspend  the  sowing  of 
wheat  for  two  year-.  In  1839  c  the  pest  again  became  destructive  in 
the  Carolinas  and  in  Virginia,  where  the  bugs  migrated  from  the 
wheat  fields  at  harvest  to  the  corn,  and  in  1840  there  was  a  similar 
outbreak,  and  both  wheat  and  corn  we're  seriously  injured.  In  all 
of  these  cases,  however,  there  is  no  recorded  estimate  of  the  actual 
financial  losses  resulting  from  the  attack-  of  the  chinch  bug.     Accord- 


FlG.   9. 


Brachyrhynchus  </ranulatus:  a,  early   nymph;  b,  adult;  c,  late 
nymph.    All  enlarged  (original). 


a  Webster  on  Pestilence,  Vol.  I.  p.  279.     No1  seen. 
6  Albany  Cultivator,  Brs1  series,  Vol.  VI,  p.  201. 
cThe  Cultivator,  Vol.  VI,  p.  103. 


Quoted  from  Fitch. 


26608— No.  69— «>7  >i- 


-•; 


34  THE    CHINCH     BUG. 

ing  to  Le  Baron,  during  the  yriw^  from  L845  to  ls">0  the  insect 
ravaged  over   Illinois  and  portions  of  Indiana  and   Wisconsin,  and 

in  1S.~>1  and  1855  it  again  worked  serious  injury  in  northern  Illinois. 
The  writer's  earliest  recollection  of  the  chinch  bug  and  it-  ravages 
in  the  grain  fields  of  the  settlers  on  the  prairie-  date-  from  this 
last  outbreak.  Mr.  B.  D.  Walsh  estimated  the  loss  to  the  farmers 
of  [llinois  in  L850  at  $4,000,000,  or  $4.70  to  every  man.  woman,  and 
child  living  in  the  State.  The  earlier  outbreak-,  though  the  occa- 
sion of  smaller  money  loss,  were  even  more  disastrous;  for  the 
destruction  of  the  grain  crop-  in  those  pioneer  days  not  only  took 
away  all  cash  profits,  but  also  deprived  the  early  settlers  of  their 
\«i-\   living,  and  in  some  cases  reduced  them  to  starvation. 

Iii  L863,  lv<d.  and  L865  the  insect  was  again  destructive  in  Illinois 
and  other  Western  State-,  it-  ravages  being  especially  severe  in  L864, 
when  we  have  another  attempt  at  computation  of  the  financial  loss. 
J)r.  Henry  Shimer,  of  Mount  Carroll,  111.,  who  had  carefully  studied 
the  chinch  bug,  estimated  that  "three-fourths  of  the  wheat  and  one- 
half  of  the  corn  crop  were  destroyed  by  the  pest  throughout  many 
extensive  districts,  comprising  almost  the  entire  Northwest."  In 
criticising  the  doctor  regarding  another  point.  Messrs.  Walsh  and 
Riley,  in  The  American  Entomologist  (Vol.  I.  p.  197.  1869),  admit 
that  the  estimate  was  **  a  reasonable  one."  and.  taking  it  a-  a  basis, 
with  the  actual  cash  price  per  bushel,  computed  the  loss  at  about 
oO.OOO.OOO  bushels  of  wheat  and  138.000,000  bushels  of  corn,  with  a 
total  value  of  both  amounting  to  over  $73,000,000.  Of  course  all 
computations  of  this  sort  are  necessarily  only  approximately  cor- 
rect, but  there  i>  more  likelihood  of  an  under  than  an  over  estimate 
in  this  case. 

There  was  a  serious  outbreak  of  the  chinch  bug  in  the  West  again, 
in  the  year  1868,  and  again  in  1871.  but  in  187-1  the  ravage-  were  both 
widespread  and  enormous.  Doctor  LeBaron  computed  the  loss  in 
1871  in  seven  State-,  viz.  Iowa.  Missouri.  Illinois  Kansas,  Nebraska, 
Wisconsin,  and  Indiana,  at  $30,000,000.°  Doctor  Riley  computed  the 
loss  in  Missouri  alone  in  the  year  1874  at  $19,000,000.  and  added  the 
statement  that  for  the  area  covered  by  Doctor  LeBaron's  estimates  in 
L871  the  loss  in  ls7i  might  safely  be  put  down  as  double,  or  upward 

of  sr,o. .Hun.      Dr.  Cyrus  Thomas,  however,  estimates  the  loss  to 

the  whole  country  for  the  same  year  at  upward  of  $100,000,000.' 

The  next  serious  outbreak  of  the  chinch  bug  of  which  we  have  the 
losses  resulting  therefrom  computed,  occurred  in  L887,  and  covered 
more   <>r   le--   territory    in    the   States   of    Kentucky.   Ohio.   Indiana. 

cond  Report  State  Entomologist  of  Illinois,  p.  144. 
niii  Report   State  Entomologisl  "f  Missouri,  pp.  24-25 
Bulletin  X".  5,  I".  s.  Entomological  Commission,  j>.  7. 


LOSSES    CAUSED    in     CHINC 


BUGS. 


35 


[llinois,  Wisconsin,  Minnesota,  Iowa.  Missouri,  and  Kansas.  In  dii> 
case  the  damage  was  estimated  by  the  United  States  statistician,  Mr. 
J.  R.  Dodge,  at  $60,000,000,  the  heaviesl  losses  occurring  in  Qlinois, 
Lowa,  Missouri,  and  Kansas.^  This  gives  us  as  the  estimated  loss 
in  the  thirty-eight  years,  L850  to  L887,  both  inclusive,  the  enormous 
Mini  of  $267,000,000. 

There  was  a  serious  outbreak  in  Kansas,  Iowa.  Minnesota,  and  Illi- 
nois, having  its  beginning  probably  as  early  as  L892,  bui  peaching  its 
maximum  severity,  as  in  Ohio,  in  L896.  The  loss  in  Ohio  during  the 
year-  L894,  L895,  1896,  and  L897  could  not  have  fallen  far  short  of 
$2,000,000.     The   farmers  of  this  State  in  many  cases  were  entirely 


10.      .Map   showing  areas   in   the    United  States  over  which    the   chinch  bug   occurs    in 
greatest   abundance  and  may  at  any  time  become  destructive.      (Original.) 

unfamiliar  with  the  chinch  bug  and  its  ravages,  and  therefore  were 
unable  to  account  for  the  damage  that  it  worked  in  their  fields  until 
some  time  after.  This  was  especially  true  of  the  timothy  meadows  in 
the  northeastern  part  of  the  State;  so  that  there  were  probably  many 
fields,  both  of  grass  and  of  grain,  that  suffered  seriously,  and.  in  fact, 
'ii  some  cases  were  ruined  bv  the  chinch  bus:  without  the  owners  being: 
aware  of  the  cause.  For  this  reason,  while  the  computed  loss  appears 
large,  it  seems  to  me  to  be  entirely  reasonable.  Of  the  losses  occa- 
sioned in  other  States  during  the  year-  above  indicated  no  definite 
computations  are  available,  bui  they  were  severe,  and  musl  have 
amounted  to  millions  of  dollars.  If  we  could  have  careful  estimates 
of  the  loss  during  the  last  fifteen  years,  it   would  in  all  probability 

<*  Report  of  U.  S.  Commissioner  of  Agriculture.  1887.  p.  56. 


36  THE    CHINCH    BUG. 

swell  ili»'  amount  to  considerably  in  excess  of  $330,000,000  for  the 
period  from  L850  to  L906.  Within  the  last  ten  years  the  insect  has 
become  more  injurious  in  Oklahoma,  western  Kansas,  and  northern 
Texas,  localities  not  included  in  these  estimates,  and  although  the 
spring  rain-  serve  to  destroy  the  young  bugs,  outbreak-  in  northern 
Texas  and  ( Oklahoma  are  not  rare  in  held-  of  wheat,  corn,  and  barley. 
II"  the  indirect  losses  were  to  he  added,  the  amount  would  indeed  hi' 
enormous.  During  the  outbreak  in  Ohio  at  least  two  farmer-  became 
discouraged,  and.  thinking  that  the  loss  of  their  crop-  by  the  attack 
of  chinch  bugs  would  result  in  their  financial  ruin,  in  their  despond- 
ency they  sought  relief  in  suicide. 

When  we  take  into  consideration  that  the  financial  losses  as  above 
estimated  have  not  fallen  upon  the  entire  nation,  but  almost  without 
exception  upon  the  nine  States  previously  named  (see  fig.  10),  it  will 
be  -ecu  that  this  diminutive  insect  constitutes  a  formidable  enemy  to 
the  agriculturist  of  these  States.  In  fact,  small  a-  it  i-.  this  pest  has 
cost  the  people  of  these  nine  States  a  sum  of  money  which,  a  few 
years  ago,  would  have  defrayed  the  entire  expense  of  the  National 
Government  for  a  whole  year.  Fire  excepted,  there  is  probably  no 
other  factor  that  has  caused  such  an  enormous  financial  loss  within 
the  same  period  over  the  same  area  of  country. 

NATURAL  CHECKS. 

All  adverse  natural  influences  affecting  the  chinch  bug  will  be 
treated  under  this  head,  with  the  exception  of  animal  and  vegetable 
foes,  which  are  considered  here  as  natural  enemies. 

INFLT  KM  E    OF    PRECIPITATION    OX    THE    CHINCH    BUG. 

There  is  probably  no  more  potent  factor  in  restraining  the  increase 
in  numbers  of  this  species  than  is  to  be  found  in  meteorological  influ- 
ences consequent  upon  rain.  The  fact  has  long  been  known  that  the 
years  of  greatest  abundance  of  the  chinch  bug  were  preceded  by  a 
series  of  years  luring  wdiich  there  had  been  a  deficiency  in  the  rainfall 
over  the  area  of  country  devastated  by  this  -pecies.  In  fact,  it  has  in 
a  genera]  way  come  to  lie  understood  that  dry  seasons  are  favorable 
and  wet  seasons  unfavorable  for  the  development  of  the  chinch  bug, 
though  the  details  of  the  phenomenon  have  never  been  very  carefully 
and  elaborately  worked  out.  The  entomological  and  meteorological 
records  of  the  past  have,  however,  clearly  shown  that  the  amount  of 
the  annual  rainfall  i-  not  a  safe  guide  in  this  problem.  Chinch  bugs 
have  occurred  in  excessive  number-  during  years  of  heavy 
precipitation. 

The  term  "  wet  season,"  so  frequently  used  in  this  connection,  is  an 
indefinite  one.  but  if  the  term  "  season  "  be  restricted  to  the  period  of 
Lime  intervening  between  the  vernal  and  autumnal  equinoxes  we  shall 


INFLUENCE   OF   TEMPERATURE    ON    CHINCH    BUG.  37 

have  more  definite  grounds  upon  which  to  base  our  studies  of  meteoro 
Logical  influences.  Thus  applied,  the  terms  -  wel  "  and  "dry  "  sea- 
sons would  include  within  them  the  two  breeding  periods  of  the 
chinch  bug,  ;it  least  largely  so,  north  of  latitude  30  N.  Bui  the  his- 
tory of  this  species  has  shown  thai  there  may  he  an  excess  of  rain  fall 
during  this  critical  period  and  that  -till  a  sufficient  number  of  insects 
may  develop  to  work  serious  injury  over  considerable  areas  of  coun- 


Pio.il.-    Map  showing  distribution  of  chinch  bug  in  Ohio  in  1896.     (Author's  illustration.) 

try.  This  is  due  to  two.  and  perhaps  more,  causes.  In  the  first 
place,  an  unusually  heavy  rainfall  at  long  intervals,  while  bringing 
up  the  total  for  a  given  period,  may  have  hut  little  effect  in  reducing 
the  number  of  chinch  bugs,  while  a  much  less  amount  of  precipitation 
coming  at  short  intervals  and  in  the  midst  of  the  hatching  season 
would  cause  a  far  greater  mortality  among  the  young.  And.  in  the 
second  place,  the  precipitation  may  come  at   the  beginning  or  even 


38 


Till:    CHINCH    BUG. 


before  the  commencement  of  this  breeding  season  or  just  at  the  close 
thereof,  thus  enabling  the  major  portion  <>i*  the  young  to  reach  a 
period  in  their  development  wherein  they  are  little,  if  at  all,  -u-- 
ceptible  to  the  effects  of  drenching  rain-.  This  was  clearly  illus- 
trated in  southern  ( >hio  during  the  spring  of  L896,  and  again  in  1697. 
Throughout  southern  Ohio,  in  L896,  between  latitude  38c  30'  and  39c 
lu\  as  the  reports  of  the  United  State-  Weather  Bureau  -how.  there 


*A.RFlEU>        |~  PtSRV^     L L- 


r«««  scto* 


Fig.  12.     Map  showing  distribution  of  ch:ncb  bug  in  Ohio  in   1! 


i  Author's  illustration. 


had  been  but  very  little  rain  up  to  May  11.  and  no  general 
rain  until  May  25.  The  effect  upon  the  young  bugs,  judging  from 
the  destruction  which  they  caused,  would  seem  to  have  been  to 
destroy  only  the  latest  to  hatch.  Leaving  the  earlier  developing 
young  sufficiently  advanced  to  withstand  the  effects  of  the  later  and 
heavier  rain-.  The  accompanying  map  (fig.  11)  will  show  the  areas 
over  which  chinch  bugs  were   reported   marked  thus        .  while  the 


INFLUENCE    OF    PRECIPITATION    ON    cilixcil     BTH 


J9 


area  seriously  ravaged  is  indicated  thus    #,  showing  thai   the  ruin 
came  too  late  in  such  a  section  to  ward  off  an  outbreak  of  the  pest 

According  to  t he  Weather  Bureau  reports  also,  the  distribution  of 
rain  in  May,  ls(.»7.  differed  materially  Prom  that  of  the  same  month 
of  L896  in  that  in  L897  the  major  portion  of  the  rain  fell  prior  to 
the  L5th,  the  remainder  of  the  month  being  rather  dry.  the  only 
general   precipitation  occurring  on   the  23d   and  24th,   with   a   much 


Pio.13.-    Map  showing  distribution  of  chinch  bug  in  Ohio  in  1894.     (Author's  illustration.) 

lighter  rain  on  the  28th.  But  here  again  the  amount  was  insufficient 
to  ward  off  serious  injury,  as  is  indicated  by  map  (fig.  L2),  the  same 
symbols  being  \\-^\  here  as  before.  In  this  case  it  was  probably  the 
latter  portion  of  the  brood  that  survived,  as  a  personal  inspection 
of  the  country  early  in  the  month  failed  to  reveal  the  presence  of 
young  hm!--.  though  they  were  certainly  present  in  abundance  at  a 
corresponding  period  of  the  preceding  year. 


40  THE   CHINCH    BUG. 

Thai  the  amount  and  frequency  of  rain  during  the  month  of  Mai 
has  very  much  to  do  with  the  ravages  of  chinch  bugs  when'  sufficient 
numbers  have  wintered  over  to  produce  the  requisite  number  of 
young,  is  further  shown  by  the  fact  that  in  L894  the  only  locality 
where  serious  ravages  were  committed  was  in  Wyandot  County,  as 
shown  on  map  (fig.  L3),  and  this  was  one  of  the  few  area-  in  Ohio 
where  the  precipitation  during  that   month  was  less  than  3  inches. 


Rainfall 


Chinch  Bug 


'Areas  infested     §8&fGreatly  infeste 


Under 
1  inch 

— 1  to2= 

- 

Er2t~4= 

lOwr-Asj 

Fig.   11.     Map  showing  distribution  of  cnincb  oug   in  Ohio  in   1895,  :m<l  amount   of  pre 
cipitation  over  the  State  during  May  of  the  same  year.      (Author's  illustration.) 

Except  over  a  circular  area  covering  less  than  one-half  of  the  county 
the  amount  of  precipitation  was  3  to  5  inches,  and  this  area  includes 
that  ravaged  by  the  chinch  bugs  during  the  following  month. 

Still  more  striking,  however,  is  the  relation  between  the  two 
phenomena  during  the  following  year.  The  last  of  this  series  of 
map-  (fig.   I  I  )  shows  the  area  over  which  chinch  bugs  were  reported 


1XFI. n:\iT    OF    PRECIPITATION    <»\    CHINCH     BUG.  11 

and  the  area  where  their  Injuries  were  the  most  severe;  also,  by 
horizontal  lines,  the  areas  over  which  the  amount  of  precipitation 
was  the  Least.  From  this  it  will  be  observed  thai  in  all  of  the  seri 
OUsly  affected  area,  and  ill  nearly  all  of  the  area  over  which  the 
pest  was  reported  at  all.  the  precipitation  during  the  month  of  May, 
L895,  was  from  1  to  2  inches,  the  extension  of  the  point  westward 
into  Shelby  County  being  especially  interesting.  It  may  be  said 
with  regard  to  the  occurrences  outside  of  this  area  of  light  precipita- 
tion that  the  exact  Localities  were  probably  not  indicated,  as  the 
'information  was  secured  from  farmers,  and  their  location-  as  indi- 
cated on  the  map  were  their  post-ollice  addresses,  which  might  have 
been  several  miles  away  in  any  direction,  and  the  isolated  point-  of 
attack  were  often  based  upon  one  or  two  reports.  If  exact  localities 
could  have  been  obtained,  and  the  precise  area  of  precipitation  indi- 
cated, the  connection  between  the  two  phenomena  would  have  been 
shown  more  correctly,  and  would  probably  have  revealed  an  even 
greater  uniformity  than  is  now  apparent.  It  must  be  understood, 
however,  that  in  these  calculations  northeastern  Ohio  i-  excluded, 
and  the  writer  believes  that  what  is  true  of  the  rest  of  the  State 
will  be  found  to  be  equally  correct  as  regarding  territory  occupying 
the  same  latitude  westward  to  the  limit  of  this  area  of  distribution. 
While  it  is  probable  that  the  effect  of  precipitation  during  August 
would  have  a  similar  influence  on  the  second  brood  of  young,  and. 
consequently,  upon  the  number  of  adults  which  would  go  into  winter 
quarters,  yet  a  careful  study  of  the  two  factors  shows  that  meteoro- 
logical conditions  in  August  have  a  far  less  influence  upon  the  fol- 
lowing brood  than  do  those  of  May.    • 

Owing  to  causes  which  are  as  yet  unknown  to  the  writer  the  same 
laws  do  not  apply  to  the  northeastern  part  of  Ohio  and  to  what  we 
have  termed  the  west-bound  tide  of  migration.  Here,  and  as  against 
the  more  or  less  short-winged  form  of  chinch  bug,  meteorological  con- 
ditions appear  to  exert  a  far  les^  potent  influence.  What  is  true  of 
meteorological  conditions  during  May  elsewhere  in  Ohio,  seems  to 
be  partly  true  of  June  in  the  northeastern  portion  of  the  State, 
though  there  is  not  the  evidence  of  the  effect  of  precipitation  here 
that  we  have  elsewhere.  Doctor  Lint ner,  in  his  Second  Report,  while 
discussing  the  outbreak  of  the  chinch  bug  in  New  York  during  1  882  s  •"> 
calls  attention  to  the  fact  that  both  in  1881  and  L882  there  was  an 
excess  of  precipitation.  On  page  L58  of  his  report  Doctor  Lintner 
says  that  spring,  summer,  and  autumn  were  exceptionally  wet.  In 
spring  heavy  and  continued  rains  flooded  meadows  which,  later. 
showed  the  effect  of  chinch-bug  attack'.  Even  at  haying  time  while 
the  bugs  were  young  and.  according  to  all  accounts,  easily  killed 
by  heavy  rains,  they  persisted  in  multiplying  and  Living  despite 
the  fact   that   rain-   were  SO   freuuent    and   severe  that   only  a    portion 


42  Till.    CHINCH    BUG. 

of  the  hay  could  be  gathered  in  a  proper  condition.  This  was  the 
state  of  affairs  on  July  5  when  the  hay  was  cut,  and  on  October  10 
Doctor  Lintner  stated  thai  owing  to  continued  rain-  grass  was  -till 
lying  in  the  fields  and  could  not  lie  gathered,  while  fields  of  oats 
remained  unharvested.  In  all  of  the  reports  given  of  this  outbreak 
it  was  stated  that  the  damage  was  first  observed  in  August  or  Sep- 
tember, and  it  i-  believed  that  this  will  hold  good  as  applied  to 
northeastern  ( )hio. 

A-  ha-  been  stated,  the  females  oviposit  a-  a  rule  at  or  just  below 
the  surface  of  the  around,  and  the  young  make  their  way  upward 
in  order  to  secure  food.  In  case  of  cultivated  grains  this  mode  of 
procedure  is  absolutely  imperative,  a-  the  bases  of  the  plant-  are  at 
thai  time  loo  tough  and  woody  to  offer  sufficient  food.  Bui  in  the 
case  of  timothy  the  conditions  are  entirely  different,  as  the  hull)  of 
this  plant,  situated  just  below  the  surface  of  .the  ground  and  con- 
venient to  the  place  of  oviposition,  furnishes  an  ample  supply  of 
Pood  without  making  it  necessary  for  the  young  to  crawl  upward 
in  order  to  secure  it.  Then,  too.  the  surface  of  the  ground  in  cul- 
tivated fields  is  nearly  or  quite  free  of  dead  leaves  and  >tems.  there 
being  little  hut  the  vertical-growing  plant-  to  afford  protection  from 
the  weather.  In  timothy  meadoAvs  the  surface  of  the  ground  is 
usually  covered  to  the  depth  of  an  inch  or  more  with  dead  and  decay- 
ing stubble  and  leaves,  and  the  top  of  the  ground  itself  is  often  more 
or  less  loose  and  mellow  in  the  immediate  proximity  to  the  bulbs  of 
the  plants.  It  would  appear  that  we  might  here  have  a  partial  solu- 
tion of  the  problem  of  the  vital  effects  of  precipitation  on  the  young 
hugs.  Besides,  for  aught  we  know,  the  progeny  of  tlii-  quite  short- 
winged  form  may  he  better  able  to  withstand  naturally  the  effect  of 
drenching  rains  than  that  of  the  east-bound  long-winged  form.  We 
must  recollect  that  in  the  one  ease  the  progenitors  have  worked  their 
way  over  hot.  arid  plain-  a-  well  as  cool,  damp  prairies,  while  in  the 
other  case  the  tide  of  migration  lay  between  the  more  elevated  lands 
and  the  sandy  beaches  of  the  seashore  where  there  was  always  a  more 
or  less  near  proximity  to  the  ocean,  until  the  tide  of  migration  left  the 
seashore  and  drifted  westward  over  New  York  and  onward  into 
northeastern  Ohio.     (See  map.  fig.  17.) 

This  influence  of  precipitation  on  the  young  chinch  bug-  while  in 
the  act  of  hatching,  and  that  of  temperature  upon  the  adult-  in  winter. 
some  illustrations  of  which  have  been  included  under  the  subjeci  of 
hibernation,  are  the  only  cases  where  meteorological  condition-  appear 
to  have  a  direct  effect  on  this  species.  A-  previously  shown,  the  tem- 
perature effects  are.  hugely  at  least,  unfavorable  for  such  adult-  as 
may  happen  to  be  more  or  less  unprotected  during  the  hibernating  sea- 
son.    Upon  this  point  it  might  be  well  to  suggesi  that  this  protection, 


INFLUENCE   OF   PEEClPITATIOH    ON    CHINCH    BUG.  Ill 

which  may  be  composed  of  leaves  and  dried  grass,  may  be  burned  :i\\  a\ 
in  early  winter  and  thus  leave  the  insects  without  the  expected  protec 
fcive  covering,  or  this  covering  may  be  still  further  augmented  by  a 
mantle  of  snow,  which,  remaining  for  a  more  or  less  prof  racted  period 
of  time,  counteracts  the  influences  of  temperature,  and  the  latter  then 
becomesa  factor  of  secondary  importance  in  the  problem  of  life  among 
chinch  bugs.  It  is  very  doubtful  if  temperature  is  as  vital  in  its  ef 
fects  as  are  the  indirect  influences  of  precipitation  during  the  breeding 
season. 

It  has  long  been  understood  that  the  two  species  of  entomogenous 
fungi,  Sporotrichum  globulifemm  Speg.  and  Entomophthora  aphidis 
Iloll'ni..  both  of  which  attack  the  chinch  bug,  require  for  their  rapid 
development  an  atmosphere  heavily  charged  with  moisture,  and  that 
without  this  neither  of  these  becomes  sufficiently  abundant  to  cause 
any  serious  mortality  among  the  insect  host,  but  this  matter  will 
receive  attention  in  the  discussion  of  these  parasitic  foes  farther  on. 

INFLUENCE   OF  TEMPERATURE   OX    THE   CHINCH    BUG. 

Idie  writer  would  call  attention  here  to  a  possible  influence  of 
temperature  upon  what  he  has  termed  the  west-bound  tide  of  migra- 
tion. When  the  time  arrives  for  the  hibernating  adults  to  leave 
their  winter  quarters  and  disperse  over  the  fields  prior  to  oviposit  ion. 
if  the  weather  should  prove  too  severe  they  have  but  to  remain  in 
these  quarters  a  while  longer  until  more  favorable  weather.  Thus, 
along  the  northern  Atlantic  coast  the  season  is  generally  much  later 
near  the  shore  than  it  is  a  few  miles  inland,  and  Mr.  Schwarz a 
has  called  attention  to  the  influence  which  this  phenomenon  exerts 
upon  the  chinch  bug.  Now,  this  retardation  amounts  probably  to 
about  a  month  in  spring,  which  would  have  a  tendency  to  delay  ovi- 
posit ion.  especially  among  the  short-winged  females.  If  this  were 
continued  through  a  long  period  of  time,  consequent  upon  the  slow 
movement  of  this  tide  of  migration  northward  along  the  coast,  it 
would  hardly  be  surprising  to  find  that  this  retarded  activity  in 
spring  had  become  so  characteristic  as  to  be  retained  after  this  tide 
had  swepl  to  the  westward,  and  resulted  in  the  species  being  thus 
single  brooded  in  the  East,  while  it  is  double  brooded  in  the  east- 
bound  tide  of  migration  in  the  West.  This  effect  of  a  long  habita- 
tion along  the  shores  of  the  northern  Atlantic  would  be  to  some  extent 
encouraged  by  the  prolonged  northern  winter  and  the  correspond- 
ingly -horter  period  during  which  the  s|)(.rj,.s  could  breed,  and  thus 
in>tead  of  the  effects  of  the  old  environment  becoming  obliterated 
they  might  be  continued,  or,  as  in  case  of  the  fore-shortening  of  the 
wings. -till  further  intensified.     If  the  effect  of  this  prolonged  period 


"  [nsect  Life,  Vol.  vn.  p.  422. 


44  the  chinch   BUG. 

of  hibernation  has  been  to  reduce  the  number  of  broods,  then  it  \\'\\\ 
have  to  be  considered  as  a  natural  check,  in  that  to  a  certain  extent  it 
prevents  excessive  abundance  by  reducing  the  number  of  offspring. 
This  would  also  account  for  the  rather  surprising  immunity  that  has  j 
heretofore  been  enjoyed  by  the  northeastern  portion  of  the  country 
from  the  ravages  of  this  destructive  species. 

NATURAL   ENEMIES. 

It  is  possible  that  there  are  some  reasons  winch  might  appear  to 
justify  the  placing  of  fungous  enemies  of  the  chinch  bug  among  the 

natural  check-,  as  they  no  doubt  do  exert  a  more  or  Less  powerful 
influence  in  that  direction,  but  it  seems  more  convenient  to  include 
them  among  natural  enemies,  especially  as  one  at  least  has  come  to  be 
applied  artificially  to  overcome  the  insect.  The  fact  that  the  abun- 
dance and  consequent  influence  of  these  fungous  enemies  is  almost 
entirely  dependent  upon  meteorological  condition-  is  sufficient  to 
place  them  in  a  secondary  position,  even  though  they  may  under 
favorable  meteorological  conditions  act  as  natural  cheeks.  All.  doubt- 
less, have  other  host  insects,  and  the  two  most  important  have  been 
known  to  break  out  again  and  again  spontaneously  and  destroy  myr- 
iads of  chinch  bugs  when  the  latter  were  present  in  excessive  numbers. 
But  this  has  taken  place  only  in  connection  with  the  necessary  pre- 
cipitation: hence  these  fungi  become  natural  enemies  only  under 
certain  favorable  weather  conditions;  and  though  their  season  of 
most  potent  effect  is  during  the  time  when  the  chinch  bug  i-  develop- 
ing from  the  egg  to  the  adult,  yet  as  shown  by  observation  they  may 
exert  powerful  and  fatal  effects  among  the  adults,  where  these  last 
have  congregated  together  in  masses. 

PARASITIC    FUNGI. 

The  two  -pecies  of  entomogenous  fungi  to  which  reference  has  just 
been  made  are  Entomophthora  apkidis  Hoffman-'  and  Sporotriehum 
globuliferum  Speg,6  both  having  probably  been  associated  in  destroy- 
ing the  chinch  bug  spontaneously  in  the  fields,  and  doubtless  were 
distributed  to  correspondents  by  Professor  Snow  and  others  to  be 
artificially  established  in  fields  where  there  was  an  overabundance  of 
chinch  bugs.  For  this  reason  it  is  impossible  to  separate  the  effects 
of  tlit-  two  in  the  earlier  literature,  even  the  first  observations  of  Dr. 
Henry  Shinier'    probably  applying  to  their  joint   effect. 

Hoffman,  in  Fresenius's  "  Entoniophthorea?,"  p.  208,  figs.  59-67. 
6  Spegazzini,  "Fungi  Argentini,"  II.  p.  42. 
■  Proc.  Acad.  Nat.  Sci.  Phila.,  May,  1867. 


PARAS]  I  U      FUNGI.         '  1,1 

Doctor  shinier,  however,  was  the  first  to  call  attention  to  the  \\  ide 
spread  ami  fatal  e fleets  of  fungous  diseases  among  chinch  bugs, 
and  while  his  explanations  therefor  seem  now  crude  and  illogical, 
lii>  observations  were  made  with  Mich  care  and  accuracy  that  we  have 
not  yet  had  occasion  to  materially  revise  them.  Under  date  of  July 
16,  [8(»r>,  he  makes  this  observation:  "  :::  :::  :::  I  found  many  dying 
on  the  low  creek  bottom  land  from  the  effects  of  some  disease,  while 
they  are  yet  in  the  larval  state  a  remarkable  and  rare  phenomenon 
for  insects  thus  in  such  a  wholesale  manner  to  be  dying  without  at- 
taining their  maturity,  and  no  insect  enemy  or  other  efficient  cause 
to  be  observed  capable  of  producing  this  important  result."  A.gain, 
under  date  of  duly  22:  "On  low  grounds  the  chinch  bugs  are  dead 
from  the  disease  above  alluded  to,  and  the  same  disease  is  spreading 
to  the  hills  and  high  prairies." 

Under  this  date  also  he  speaks  of  the  very  wet  weather,  and  states 
that  in  a  barley  field  the  chinch  bugs  began  to  die  at  about  the  same 
time  that  they  did  on  the  low  creek  bottom,  and  that  they  rapidly  met 
the  same  fate,  so  that  few  of  them  lived  to  find  their  way  to  a  neigh- 
boring cornfield,  while  under  date  of  August  8  he  states  that  of  those 
that  migrated  to  the  cornfields  "  very  few  are  to  be  found  remaining 
alive;  but  the  around  around  the  base  of  the  cornhills  is  almost  liter- 
ally covered  with  their  mouldering,  decomposing  dead  bodies.  They 
are  dead  everywhere,  not  lying  on  the  ground  alone,  but  sticking  to 
the  blades  and  stalks  of  corn  in  great  numbers,  in  all  stages  of  de- 
velopment, larva,  pupa,  and  imago." 

"  This  disease  among  the  chinch  bugs  was  associated  with  the  long- 
continued  wet,  cloudy,  cool  weather  that  prevailed  during  a  greater 
portion  of  the  period  of  their  development.     *     *     *  " 

These  are  precisely  the  conditions  under  which  these  fungi  have 
been  observed  to  prove  the  most  fatal  to  the  chinch  bug  during  recent 
years,  where  their  introduction  among  the  host  insects  was  accom- 
plished by  artificial  means.-  Although  Doctor  Shinier  probably  never 
anticipated  the  artificial  cultivation  of  his  "disease,"  and  the  results 
which  have  since  been  obtained  from  its  artificial  dissemination  in  the 
held-,  yet  his  careful  and  painstaking  studies  must  ever  be  associated 
with  the  application  of  fungous  diseases  in  the  destruction  of  insects 
in  America.  It  is  certainly  to  be  regretted  that  such  practical  ento- 
mologists as  Mr.  B.  D.  Walsh  and  Dr.  C.  V.  Riley  should  have 
expressed  themselves  so  discouragingly  regarding  Doctor  Shimer's 
observations  and  conclusions,  Doctor  Riley,  as  late  as  1870,  even 
going  so  far  as  to  ridicule  the  theory  of  disease  being  in  any  way 
responsible  for  the  death  of  the  chinch  bug-  observed  by  Doctor 
Shinier.'' 

a  Second  Report  State  Entomologist  of  Missouri,  pp.  D4-25,  1870. 


46  •      THE    CHINCH    BUG. 

It  was  not  until  ls7'.>  thai  an  entomologist  came  t<>  the  rescue  of 
Doctor  Shimer's  theory  of  disease  among  chinch  bugs.  Dr.  Cyrus 
Thomas,  in  Bulletin  No.  5  of  the  United  State-  Entomological  Com- 
mission, L879,  page  24,  stated  that  while  Doctor  Shimer's  plague 
among  chinch  bugs  was  somewhat  extraordinary,  vet  it  was  in  accord- 
ance with  fact-  that  he  had  himself  ascertained  in  reference  to  other 
insects,  and  in  proof  he  cited  a  similar  whole-ale  destruction  of  flic-  in 
southwestern  Virginia  and  eastern  Tennessee  in  the  year  1849.  and 
also  a  similar  epidemic  among  grasshoppers  in  western  Minnesota, 
Dakota,  and  northern  Iowa  in  1872.  This  position  of  Doctor  Thomas 
in  support  of  Doctor  Shinier  may  he  regarded  as  a  second  step  in  our 
advance  in  a  knowledge  of  the  influence  of  meteorological  condition- 
on  the  chinch  bug.  It  paved  the  way  for  further  research  in  this 
direction. 

II   NGOl  -    ENEMIES    0]      I  111     CHINCH    BUG    DETERMINED. 

While  the  -ubject  of  epidemic  and  contagious  diseases  of  insects 
was  discussed  to  a  greater  or  less  extent  among  scientific  men.  there 
was  a  decided  lack  of  actual  experimentation,  and  none  at  all  with 
i  he  fungous  parasites  of  the  chinch  bug  until  1882  and  1883.  when 
Prof.  S.  A.  Forbes  began  what  ultimately  proved  to  be  a  long  series 
of  studies  of  the  chinch  bug  and  its  natural  enemies.  At  thi-  time. 
1882.  Professor  Forbes  was  more  especially  interested  in  the  bacterial 
diseases  of  the  chinch  bug,  and  though  he  found,  at  Jacksonville,  111.. 
many  specimens  of  dead  chinch  bugs  embedded  in  a  dense  mat  of 
white  fungous  thread-,  which  sometimes  almost  hid  the  body  and 
reminded  him  of  the  fatal  disease  previously  reported  by  Doctor 
Shinier,  yet  except  to  secure  from  Prof.  T.  J.  Burrill  a  determination 
of  this  fungus  as  belonging  to  the  Entomophthora  no  progress  was 
made  in  the  study  of  this  particular  phase  of  the  chinch-bug  problem." 

In  July.  1887.  Professor  Forbes  found  attacking  the  chinch  bug  in 
Clinton  County.  111.,  a  second  fungus,  which  he  determined  as  be- 
longing to  the  genus  Botrytis,  but  this  conclusion  has  since  been 
revised  and  the  species  i-  now  known  a>  Sporotrichum  globuliferum 
Speg.  This  discovery  of  a  second  species  of  entomogenous  fungi  and 
its  separation  from  the  Entomophthora  comprises  what  may  be  justly 
termed  a  third  step  in  the  advancement  of  our  knowledge  of  this  prob- 
lem. Professor  Forbes,  however,  seems  to  have  still  been  too  deeply 
interested  in  his  bacterial  studies  to  pay  any  special  attention  to  the 
other  phases  of  hi-  problem,  further  than  to  record  the  occurrence  of 
his  new  Botrytis  in  various  Localities  in  Illinois,  and  in  one  instance 
on  a  beetle.  Parandra  brunnea  (observed  by  Mr.  John  Marten,  at 
Champaign),  and.  similarly,  to  note  the  occurrence  of  the  still  spe- 
cifically undetermined   Entomophthora.6 

ii'ili  Reporl  of  the  State  Entomologist  of  Illinois,  pp.  47-51,  1882. 
&  Sixteenth  Report  of  the  State  Entomologist  of  Illinois,  pp.  -tu— to.  1888. 


PARASITIC    FUNGI.  17 

The  scene  of  action  now  changes  from  Qlinois  to  Kansas,  and  to 
Prof.  V.  II.  Snow  belongs  the  credil  of  first  applying  the  knowledge 
thai  had  been  gained  up  to  that  time  (1889)  by  confining  supposed 
healthy  chinch  bugs  with  others  affected  by  cither  one  or  the  other  of 
tin1  fungi,  or  possibly  both  Entomophthora  and  Sporotrichum,  and 
using  the  bugs  thus  infected  for  the  propagation,  in  the  field,  of  the 
disease  from  which  they  had  died. 

A>  early  as  L887  88  Professor  Snow  expressed,  in  the  Sixth  Bien 
nial  Report  of  the  Kansas  State  Board  of  Agriculture,  the  opinion 
that  "  in  the  warfare  of  man  against  his  insect  foes  a  most  valuable 
ally  will  be  found  in  the  bacterial  and  fungoid  diseases  which  may  be 
artificially  introduced  when  nature  fails  to  come  to  our  aid."  an 
opinion  at  that  time  largely  based  upon  the  investigations  of  Pro- 
fessor Forbes  and  his  own  observations  of  the  chinch  bug  in  Kansas, 
thus  paving  the  way  for  the  experiments  of  1889.  Professor  Snow 
had  now  obtained  a  specific  determination  of  the  fungous  disease  as 
(Empusa)  Entomophthora  aphidis  Hoffman,  although  there  is  some 
ground  for  the  suspicion  that  Sporotrichum  globuliferum  was  also 
present. 

Entomophthora  aphidis  was  already  known  to  ailed  Hemiptera  in 
Germany  and  the  United  States.  Dr.Roland  Thaxtera  Mate-  that,  a- 
early  a-  L886,  his  attention  had  been  called  to  the  attacks  of  this  fun- 
gus on  aphides  in  the  greenhouses  at  Cambridge,  Mass.,  where  it  acted 
as  a  decided  check,  and  later,  in  1887,  Dr.  L.  O.  Howard  had  called  his 
attention  to  great  quantities  of  aphides  dying  with  the  same  disease 
on  clover  near  the  Agricultural  Department  buildings  in  Washington, 
D.C. 

FIELD   AND    LABORATORY   EXPERIMENTS    IN    INDIANA. 

On  July  :20,  1889,  the  writer,  at  that  time  a  special  agent  of  the 
Division  of  Entomology  of  the  United  States  Department  of  Agri- 
culture, stationed  at  Lafayette.  End.,  received,  through  the  kindness 
of  Professor  Snow,  enough  material  with  which  to  make  some  experi- 
ment-, the  chinch  hug  being  at  that  time  \cry  abundant  at  Lafayette, 
and  an  exceptionally  good  opportunity  thus  being  offered  for  ex- 
perimentation. The  results  of  these  experiment-  were  published  in 
detail  in  Bulletin  22  (old  -eric-).  United  States  Department  of  Agri- 
culture, Division  of  Entomology  (pp.  55  <;:'>).  but  a-  this  was  the 
first  -eric-  of  experiment-  carried  <>ut  with  a  view  of  testing  with 
exactness  the  precise  effects  of  varying  degrees  of  temperature  and 
atmospheric  moisture  on  the  growth  of  the  Entomophthora,  and  care- 
fully following  out  the  progress  of  the  disease  under  varying  meteor- 

o Memoirs  Boston  Society  of  Natural  History.  Vol.  iv.  p.  17<;. 


\8 


THE    CHINCH    BUG. 


ological  conditions,  the  matter  is  here  republished  in  full,  the  bulletin 
in  which  it  was  originally  included  being  now  out  of  print. 

These  diseased  bugs  were  placed  under  glass  with  living  ones  from  the  fields, 
the  latter  being  provided  With  food  and  kept  thus  confined  for  fifty-three  hours, 
when  the  major  portion  of  them  were  placed  on  several  hills  of  corn  seriously 
infested  by  bugs,  the  remainder  with  the  dried  remains  received  from  Professor 
Snow  being  scattered  aboul  over  a  small  area  of  young  wheat  sown  for  experi- 
ment and  also  swarming  with  young  chinch  bugs.  The  hills  of  corn  on  which 
the  bugs  bad  been  placed  were  isolated  from  others,  equally  badly  infested,  by 
oarrow  frames  of  boards  placed  on  the  ground  and  the  upper  edges  covered  with 
tar.  This  last  precaution  was  taken  in  order  to  prevent  communication  with 
other  hills,  intended  as  checks  on  those  used  directly  in  the  experiment.  The 
area  of  young  wheat  over  which  infested  bugs  had  been  placed  was  not  inclosed, 
bul  its  limits  carefully  marked.  Five  days  after.  July  27,  a  single  bug  was 
found  ononeof  the  isolated  hills  of  corn  which  had  very  evidently  died  from  the 
effect-  of  Entomophthora,  and  by  the  30th  enough  others  were  found  to  show 
that  the  fungus  had  fully  established  itself  and  the  harriers  about  the  isolated 
hills  were  removed.  On  August  2  dead  bugs  covered  with  Entomophthora  were 
found  in  considerable  cumbers  about  hills  of  corn  25  feet  from  where  the  orig- 
inal colonies  had  been  placed  and  also  throughout  and  even  55  feet  beyond  the 
area  of  young  wheat  over  which  dead  and  affected  bugs  had  been  distributed. 
Daily  observations  were  now  made,  but  the  progress  of  the  disease  seemed  to 
come  to  a  standstill.  From  the  5th  of  August  up  to  the  9th  it  was  almost  im- 
possible  to  get  sufficient  material  outside  to  enable  me  to  carry  ou  laboratory 
experiments.  August  13  the  spread  of  Entomophthora  appeared  to  have  taken 
on  new  life,  and  diseased  hugs  were  becoming  much  more  numerous.  August  15 
found  diseased  bugs  172  feet  from  any  place  where  they  had  been  previously 
observed.  August  20  diseased  bugs  were  very  abundant  over  all  of  the  area 
where  disease  had  been  distributed,  and  two  days  later  examples  were  found 
a  quarter  of  a  mile  from  the  starting  point  of  the  disease.  Immediately  after 
this,  however,  another  halt  was  observed,  both  in  the  intensity  of  attack  and 
rapidity  with  which  it  spread,  due  either  to  the  dry  weather  or  to  the  fact  that 
the  bugs  had  now  all  reached  the  adult  stage  and  had  become  diffused  over  the 
country,  no  longer  congregating  together.  From  either  one  or  the  other,  or 
both  of  these  causes.  I  lost  track  of  the  Entomophthora  and  was  not  able  to  again 
find  it  in  the  fields.  It  seems  proper  to  state  here  that  chinch  bugs  were  not 
at  any  time  excessively  abundant  The  greatest  numbers  were  in  the  exact 
localities  where  the  disease  was  first  distributed,  the  congregating  at  these 
places  being  brought  about  by  the  close  proximity  to  a  large  number  of  small 
experimental  plats  of  wheat,  and  when  this  was  harvested  the  bugs  collected  en 
masse  on  the  corn  and  young  wheat.  In  connection  with  these  facts,  it  is  also 
interesting  to  note  that  from  July  15  to  August  -".1  there  were  ten  days  on  which 
rain  fell.  The  dates  of  these  rains  and  the  amount  of  precipitation  is  given 
below  : 


Date. 

Precipi- 
tation. 

Date. 

Precipi- 
tation. 

JulV    17 

Turin*. 

0.  02 

1 .  '2:. 
.20 
.04 
.13 

July  29 

Tnches. 

0.78 

L9 

.50 



9  

3.36 





18  

14 

.15 

.02 

PARASITIC    FUNGI. 


49 


With  a  view  of  learning  whether  or  not  there  was  any  difference  as  regards 
susceptibility  to  the  attack  of  Entomophthora  between  bugs  In  different  stages 
■f  development,  a  series  of  experiments  was  begun,  as  follows: 

Young  plants  of  Setaria  glauca  were  transplanted  to  a  i>o\.  and  upon  each 
plant  was  placed  a  dead  bug  covered  with  the  fungus,  and  also  healthy  larvae; 
larva?  just  on  the  point  of  pupation  :  pupae  just  prior  to  reaching  the  adult  stage, 
and  fully  developed  adults,  cadi  stage  being  placed  on  separate  plants,  and  each 
covered  with  a  small  inverted  glass  vial  designated  i>y  lettering.  As  checks, 
another  scries  was  prepared,  like  the  first  in  every  particular.  The  soil  in 
the  box  was  kept  well  moistened,  and  the  plaids  remained  fresh.  This  experi- 
ment was  made  on  August  -.  about  the  time  when  the  attack  outside  began  to 
diminish  in  Intensity.  The  following  are  the  results  of  examinations  on  the 
dates  indicated,  the  original  experiments  being  indicated  by  capitals  and  the 
checks  by  small  letters,  thus — A-a,  adult:  B-b,  young  larva?;  C-c,  older  larva?; 
D-d,  pupa'. 


Date. 

A. 

Bealthy.. 
l  dead  .... 
All  dead.. 
AH  dead.. 

a. 

B. 

b. 

C. 

c. 

D. 

Am:.     "> 
Auk-     G 

Bealthy.. 

1  dead.'... 
3  dead.... 

All  dead.. 

Healthy.. 
Healthy  .. 
3  dead.... 
All  dead.. 

Healthy.. 

Healthy  .. 
1  dead 

All  dead.. 

i  dead 

1  dead 

3  dead .... 
All  dead.. 

Healthv  . 
Healthy  . 

i  dead  ...    l  dead. 
3  dead  ...     1  d.-.-id. 

tug.  16 

All  dead. 

All  dead.    All  dead. 

On  the  same  day  this  experiment  was  begun  a  second  was  also  commenced, 
like  the  first  in  every  particular,  except  that  the  healthy  hugs  used  in  experi- 
mentation were  exposed  to  fungus-infected  individuals  for  only  five  hours  and 
then  placed  under  their  respective  glasses.  As  a  result,  on  August  15,  thirteen 
days  after,  none  had  died,  thus  strongly  indicating  that  the  Entomophthora  did 
not  exist  generally  in  the  fields,  and  that  it  could  not  be  communicated  during 
a  period  of  five  hours'  exposure. 

On  August  7  a  large  number  of  healthy  hugs  were  placed  under  glass,  with  a 
Dumber  which  had  recently  died  from  Entomophthora.  the  moisture  in  the  vessel 
being  absorbed  by  calcium  chloride.  A  check  experiment  was  also  commenced. 
where  the  material  and  the  conditions  were  the  same,  except  the  humidity  of  the 
atmosphere,  care  being  taken  to  have  the  latter  as  nearly  saturated  with  mois- 
ture as  possible.  August  10  the  original  experiment  was  divided  and  a  portion 
of  the  healthy  hugs  removed  and  placed  in  a  damp  environment,  the  remainder 
being  kept  under  the  original  dry  conditions.  The  results  on  August  22  were 
as  follows:  In  the  original  experiment,  where  the  healthy  hugs  had  been  con- 
tinually in  dry  quarters,  not  a  single  hug  had  died  from  Entomophthora.  Not 
only  this,  but  none  of  those  which  had  heen  removed  after  three  days  and  placed 
in  dry  quarters  had  died,  showing  that  the  disease  was  not  contracted  and  did 
not  develop  in  healthy  hugs,  though  kept  exposed  in  a  dry  atmosphere  for  fifteen 
days,  nor  could  it  he  originated  by  placing  in  a  damp  atmosphere  for  twelve  days 
bugs  which  had  been  exposed  to  contagion  for  three  days  in  dry  quarters.  The 
results  with  the  check  experiment  were  quite  different.  Within  live  days  after 
being  confined  with  the  Entomophthora  the  healthy  Iuilts  began  to  die  from 
effects  of  the  disease,  and  in  three  days  more  every  one  had  died  from  the  same 
cause,  their  bodies  being  covered  with  spores. 

Still  another  experiment  was  tried,  which  consisted  in  confining  a  large  num- 
ber  of  healthy  bugs  with  others  diseased  in  a  damp  environment,  and  when  the 
fungus  had  destroyed  a  portion  the  remainder  were  divided  and  a  part  removed 
to  dry  quarters.     The  result  was  that  while  those  left  in  damp  confinement  con- 

26608— No.  69—07  M 4 


50  THE    'ill  \cil     BUG. 

tinued  to  die,  none  of  those  inclosed  in  dry  environment  wore  destroyed.     As  the 

fungus  had  by  this  time  bi te  distributed  over  the  experiment  farm  so  that  1 

could  not  tell  with  certainty  whether  material  from  the  fields  was  in  a  perfectly 
healthy  condition  or  not,  no  further  experiments  were  made  in  this  direction. 

From  the  foregoing  it  will  be  observed  that  the  essential  element  in  all  of 
these  experiments  was  :m  abundance  of  moisture,  without  which  the  Ento- 
mophthora could  neither  become  established  nor  flourish  after  it  had  gained 
:t  footing.  Again,  the  extenl  to  which  the  disease  will  prove  contagious  will 
depend  upon  the  number  of  bugs.  Without  great  numbers  massed  together 
comparatively  few  would  contract  the  disease.  To  sum  up  the  matter,  there  is 
little  h«>pe  for  relict'  to  the  farmer  from  the  influence  of  Entomophthora,  except 
when  chinch  bugs  are  abundant  and  massed  together  in  greal  numbers,  and 
during  a  period  of  we1  weather.  I  have  succeeded  in  getting  the  fungus  estab- 
lished at  two  widely  located  points  in  Indiana,  and  do  not  consider  it  at  all 
difficult  to  introduce  in  localities  where  chinch  bugs  are  abundant,  provided 
the  weather  is  favorable.  But  if  it  is  ever  utilized  by  the  farmer,  which  seems 
p.  me  tn  be  at  present  .1  matter  of  considerable  doubt,  it  will  only  be  after 
the  pesl  has  become  very  abundant,  during  the  time  between  the  first  larval 
and  adult  stages  and  in  a  wet  time.  After  the  Entomophthora  has  been  intro- 
duced int'>  a  certain  held  it  will  become  diffused  only  in  proportion  as  the 
bugs  travel  about  and  healthy  bugs  come  in  contact  with  spores  from  those 
which  have  died  from  the  disease.  This  will  not  he  very  great  until  the  pupal 
eached. 

The  larva?  of  chinch  bugs  seem  to  in  some  way  understand  that  while  molting 
they  will  he  well-nigh  helpless,  and  hence  hide  themselves  away  in  vast  num- 
bers in  secluded  places.  Under  such  conditions  the  spores  thrown  from  dis- 
eased bugs  would  reach  a  larger  number  of  their  fellows.  I  have  found  adults 
hut  recently  molted  affected  by  the  Entomophthora.  After  the  bugs  acquire 
wings  and  scatter  themselves  over  the  country,  the  liability  to  contagion  will  be 
again  reduced,  unless  in  case  of  very  severe  invasions,  where,  from  force  of 
numbers,  congregating  on  or  about  food  plants  becomes  a  necessity.  Hence 
the  introduction  of  the  fungus  among  larva1  will  at  first  proceed  hut  slowly, 
and  only  in  extreme  cases  and  under  favorable  conditions  can  it  he  expected 
to  proceed  much  more  rapidly  among  adult  hugs.  In  short,  the  only  way  that 
this  fungoid  disease  seems  capable  of  being  employed  in  agriculture  is  by 
the  establishment  of  some  centra]  propagating  station  to  which  farmers  can 
apply  and  receive  an  abundant  supply  of  infected  bugs  on  short  notice.  By 
this  mean-  they  could  take  advantage  of  a  rainy  period  of  a  week  or  ten  days. 
and.  if  they  can  contrive  by  sowing  plats  of  millet  and  Hungarian  to  mas- 
the  bugs  iii  certain  localities  aboul  their  fields,  they  might  accomplish  some- 
thing  toward  warding  off  an. invasion.  But  the  possibility  of  overcoming  an 
invasion  after  it  is  fully  under  way.  as  is  almost  sine  to  he  the  case  during  a 
dry  season,  it  musl  he  confessed  is  not  very  encouraging.  My  failure  after 
repeated  experiments  to  produce  this  Entomophthora  in  the  vicinity  of  Lafay- 
ette without  the  importation  of  germs  i-  decidedly  against  the  theory  that 
mighl    he  advanced   that    the  northeastern   portion  of  the   State  was   kepi    free  of 

destructive  invasions  by  reason  of  tins  disease  brought  about  by  wel  weather. 
There  is  as  yet  no  reason  to  believe  that  the  disease  has  ever  existed  in  that 
section  of  the  state. 

The  fungus  entering  into  these  experiments  was  determined  as  an 
Entomophthora  by  Dr.  J.  C.  Arthur,  and  the  probability  is  that  it 
was  E.  aphidis,  though  it  is  possible  that  Sporotrichum  was  also 
present  and  remained  unobserved. 


PARASITIC   FUNGI.  .">  1 

llk-l     FIELD    APPLICATIONS    01     n    NGOU8    ENEMIES    01      Mil     CHINCH     BUG. 


As  has  been  stated,  tin*  credil  for  first  confining  healthv  chinch  buj 


rs 


with  those  diseased  and  utilizing  the  individuals  thus  infected  by 
trim -port  ing  them  to  sections  of  the  count  ry  supposedly  free  from  the 
disease  in  order  to  create  new  area-  of  infection,  belongs  to  Prof. 
F.  II.  Snow.  During  October,  L888,  the  year  prior  to  thai  during 
which  Professor  Snow  began  his  experiments,  Prof.  Otto  Lugger, 
of  Minnesota,  collected  a  quantity  of  diseased  chinch  bugs  al  the 
experiment  station  at  St.  Anthony  Park  and  distributed  them  to 
eighteen  different  localities  in  the  southern  part  of  the  State  where 
t ho  pest  was  known  to  occur  in  destructive  abundance.  The  diseased 
material  was  sent  out  in  tin  boxes  by  mail,  and  the  content-  of  the 
boxes,  on  arrival  at  their  destination,  were  -imply  thrown  in  any 
field  where  there  was  an  abundance  of  chinch  bugs.  Later  in  the 
season  the  condition  of  affairs  where  these  distributions  had  been 
made  was  such  that  "careful  search  in  the  majority  of  place-  failed 
to  produce  a  single  living  specimen,  while  the  trace-  of  the  disease 
were  found  everywhere."  With  a  spirit  of  caution  and  exactness 
in  every  way  most  commendable  on  the  part  of  Professor  Lugger, 
he  says:  "The  disease  spread  so  rapidly  that  even  corn  growing 
near  wheat  fields  crowded  with  chinch  bugs  was  entirely  protected, 
and  no  bugs  had  entered  it  in  all  the  places  visited  by  myself.  But 
the  writer  i-  by  no  means  satisfied  that  the  disease  was  really  intro- 
duced in  this  manner.  Is  it  not  possible  that  the  disease  was  already 
there,  unknown  to  anyone,  and  that  the  writer  had  simply  reintro- 
duced it-  germs?  The  reason  for  this  belief  is  based  upon  the  fact 
that  too  large  an  area  was  infested  by  the  disease — too  large  to  he 
readily  accounted  for  by  the  short  time  in  which  the  atmospheric 
conditions  were  apparently  in  its  favor."" 

In  this  case  Professor  Lugger  states  that  both  Entomophthora  and 
Sporotrichum  were  present  and  the  latter  was  sent  by  him  to  Pro- 
fessor Forbes,  so  there  is  the  same  confusion  of  the  two  fungi  in  this 
case  that  existed  in  the  writer'-  experiments  in  Indiana,  except  that  in 
the  one  ca-e  it  wa.-  certain  that  Kntomophthora  was  present,  while  in 
the  other  it  wa.-  the  Sporotrichnin. 

TIN.    UOIIK    oi     PBOFESSOB    SNOW    IX    KANSAS. 

Although  Professor  Snow  had  the  experience  and  observations  of 
Shinier.  Forbes,  and  Lugger  to  aid  him  in  his  first  efforts  to  apply 
the  knowledge  gained  by  these  gentlemen,  yet  it  must  be  -aid  that  it 
ha-  been  largely  due  to  his  untiring  energy  and  perseverance  that  the 
use  of  these  fungi  has  reached  the  present  state  of  importance.  It 
will  hardly  be  saying  too  much   if  we  state  that   his  persistent   un- 

a University  of  Minnesota   Experiment   Sta.,  Bui.   I,  Oct.,   1888,  pp.   i"   n 


52  THE    CHINCH    BUG. 

daunted  Labors,  in  the  face  of  much  skepticism  and  opposition,  has 
won  for  him  the  admiration  of  his  fellow-workers,  even  among  those 
who  \\  ere  long  in  extreme  doubl  as  to  the  success  of  his  labor.  He  has 
done  mt>re  than  any  other  one  person  to  call  attention  to  the  possi- 
bilities of  practical  benefits  to  be  derived  by  fanner-  themselves;  has 
done  more  to  advertise  the  merits  of  these  fungous  diseases  among 
the  masses  than  anyone  else,  and.  in  fact,  has  made  the  "chinch-bug 
fungus  "  almosl  a  household  word  over  the  entire  United  State-. 

It  is  therefore  all  the  more  to  be  lamented  that  he  should  have  ac- 
cepted and  published  in  hi-  several  reports  the  unsubstantiated  state- 
ments  of  farmers  whose  testimony  on  a  matter  of  this  nature  i>.  as 
every  entomologist  know-,  absolutely  worthless  unless  accompanied 
by  specimens.  Hi-  own  personal  experience  in  this  direction  and  in 
several  States  had  long  ago  led  the  writer  to  disregard  all  reports 
relating  to  the  efficiency  or  inefficiency  of  these  fungous  diseases 
among  chinch  bugs,  when  such  came  from  the  ordinary  farmer  with- 
out being  accompanied  by  specimens  for  examination.  The  cast 
pupal  -kin-  of  the  chinch  bug  pass  with  nonentomologists  very  well 
for  dead  hug-,  and  if  the  former  have  been  attacked  by  the  ordinary 
white  molds  the  deception,  except  to  the  eye  of  an  expert,  i-  com- 
plete. 

There  is  probably  not  an  entomologist  who  has  distributed  these 
fungous  di-ea-e-  among  farmers  who  has  not  found  just  such  con- 
dition- as  did  Professor  Lugger  in  Minnesota,  where  it  was  impos- 
sible to  determine  whether  these  diseases  had  been  introduced  arti- 
ficially or  whether  they  were  already  present  and  had  been  over- 
looked. In  the  writer"-  experience,  while  receiving  chinch  bugs  from 
different  part-  of  Ohio  to  be  infected  with  the  disease,  consignments 
have  come  to  him  with  the  insects  dying  and  others  dead  and  covered 
with  Sporotrichum,  -bowing  that  this  was  already  present  and  that 
the  very  utmost  that  we  could  expect  to  accompli-h  would  be  to  aid  in 
locally  spreading  the  contagion.  Besides  this,  the  writer  ha-  sent 
materia]  to  farmer-  sufficient  to  start  the  fungus  in  their  field-, 
knowing  perfectly  well  that  it  would  be  a  considerable  time  before 
actual  benefits  could  by  any  possibility  be  expected  to  materialize, 
and  within  a  week  received  the  astonishing  information  that  the  fun- 
gus was  -o  perfectly  successful  that  the  bugs  all  disappeared  within  a 
few  days  after  the  application  of  the  disease.  There  i-  little  doubt 
that  the  distribution  of  upward  of  7.000  boxes  of  these  fungi  to 
the  farmers  of  Kansas  ha-  accomplished  a  vast  amount  of  good,  but 
beyond  this  it  i-  impossible  to  go.  Of  Professor  Snow's  laboratory 
work  or  the  labors  of  himself  and  assistants  in  the  fields  no  criticism- 
can  be  made,  and  there  will  be  occasion  to  quote  from  these  in  future 
of  this  bulletin. 


PABASITIC    FUNGI.  53 

Sporotrichum  globuliferum^ov  at  any  rate  the  fungus  which  is  now 
passing  under  that  name,  was  lir^t  Pound  by  Professor  Forbes  to 
infest  the  chinch  bug  in  Ellinois  in  L887,  and  its  destructive  effects 
observed  in  the  fields  in  the  autumn  of  L888. 

Since  the  last-mentioned  date  the  writer  distributed  upward  of 
3,000  packages  of  this  fungus  to  the  farmers  of  Ohio  during  the  out- 
break of  the  chinch  bug  in  the  State  in  L895, 1896,  and  L897,and  knows 
from  personal  observation  and  study  that  it  is  under  certain  favor- 
able conditions  a  deadly  foe  of  this  species,  that  its  use  under  these 
conditions  is  pracl  icable,  and  that  if  its  application  can  be  made  simul 
taneously  with  the  commencement  of  the  brooding  season  it  will  prove 
effectual.  This  statement  is  made  for  the  reason  thai  as  late  as  L895 
Dr.  M.  C.  Cook,  in  his  popular  work  on  entomogenous  fungi,  "  Vege 
table  Wasps  and  Plant  Worms"  (p.  120),  states  that  "no  specie-  of 
this  genus  is  known  to  have  occurred  on  living  matter,  as  they  are 
saprophytes  pure  and  simple,  and  then,  probably,  only  as  the  stroma 
or  conidia  of  some  fungus  of  higher  organization,  possibly  the  Sphae- 
riacei."  This  statement  was  made  in  discussing  S.  densum,  but  on 
the  following  page  (1*21).  after  dealing  with  S.  globuliferum,  he  ap- 
pends the  following:  "  The  remarks  made  under  the  previous  species 
are  applicable  to  this,  which  is  not  entitled  to  rank  as  a  parasite,  but 
rather  as  an  accidental  development  upon  one  out  of  many  forms  of 
decaying  animal  matter." 

OTHEB    [NSECTS    ATTACKED   BY    SPOROTRICHUM    GLOBULIFERUM. 

Spegazzini "  described  the  species  from  Argentina  as  occurring  on 
the  dead  bodies  of  beetles,  notably  Monocrepidius  and  Naupactas 
xanthographus  Germ.  Besides  Parandra  brunnea  Fab.,  Professor 
Forbes  has  recorded  this  fungus  on  Lachnosterna  and  a  number  of 
other  Coleoptera,  and  also  on  lepidopterous  larvae,  as  well  as  on  the 
young  of  other  insects,  while  the  writer  has  infected,  artificially, 
Epicautapennsylvanica  Do  (i.  and  witnessed  an  instance  of  accidental 
infection  of  Megilla  metadata  De  G.,  but  failed  to  infect  the  harle- 
quin cabbage  bug  (Murgantia  histrionica  Hahn)  even  when  these 
were  placed  among  dead  and  dying  chinch  bugs  in  the  breeding  cages. 
In  both  cases  these  beetles  were  almost  entirely  covered  by  the  fungus 
after  Inning  to  all  appearances  died  from  its  effects.  With  respect 
to  this  matter  one  point  is  clear,  either  the  determination  of  this 
fungus  is  incorrect  or  else  Doctor  Cook-  has  made  a  very  serious  mis- 
statement, which  ought  to  be  corrected.  It  is  but  jusl  to  state,  how- 
ever, that  Professor  Forbes,  in  his  eighth  report  (p.  23),  calls  atten- 
tion to  the  fact  that  it  is  closely  allied  to  Botrvtis.  and  would  be 
placed  by  some  botanists  under  that  genus  now. 


a  Spegazzini,   Fungi   Argentini,  ii.  i>.  42. 


54  THE    CHINCB     BUG. 

!ll:-l     AkiMHlAl     CULTIVATIONS    OF    SPOROTBICHUM    GLOBT7LIFERTJM. 

Iii  A"|>ril.  L891,  Dr.  Roland  Thaxter  succeeded  in  cultivating  S. 
globuliferum  artificially  on  agar-agar,  and  a  month  later  Professor 
Forbes  made  similar  cultures  on  the  mixture  of  corn  meal  and  beef 
broth,  this  last  being  an  exceedingly  valuable  discovery,  as  it  revolu- 
tionized our  method  of  distributing  the  fungus  by  securing  chinch 
bugs  to  be  kept  for  a  time  with  those  diseased  and  then  sent  out  to  be 
scattered  over  the  field: — a  cumbersome  method  which  was  never  satis- 
factory. The  writer's  own  work  in  Ohio  was  based  on  material  ob- 
tained from  Professor  Forbes,  and  the  first  year  he  distributed  in- 
fected chinch  bugs,  but  after  that  be  \\-v^\  the  artificial  base  of  beef 
broth  and  corn  meal,  finding  the  latter  far  more  satisfactory  to 
handle,  and.  so  far  as  could  be  determined,  equally  effective. 

RESULTS  OF   FIELD  APPLICATIONS   IX  OHIO. 

In  regard  to  the  writer's  own  experience,  it  is  unnecessary  to  go 
into  details,  except  to  state  that,  under  the  most  favorable  laboratory 
conditions,  he  was  able  to  kill  apparently  perfectly  healthy  chinch 
bugs  within  three  day-  after  bringing  them  in  contact  with  the  Spo- 
rotrichum.  In  the  fields,  during  the  season  of  1895,  though  upward 
of  750  packages  of  diseased  bugs  were  sent  out  to  farmer-,  and  -ome 
astonishing  reports  of  results  received  therefrom,  yet  his  own  obser- 
vations led  him  to  believe  that  in  many  cases  these  were  rather  more 
imaginary  than  real.  Over  the  areas  where  local  showers  occurred 
during  the  season  of  development  of  the  first  brood  of  young  the 
effect  was  much  more  satisfactory7.  But  in  many  cases  the  request 
for  help  came  hue.  and  soon  after  the  fungus  was  applied  the  bugs 
scattered  out  over  the  fields,  disappearing  to  the  eyes  of  the  ordinary 
farmer,  who.  of  course,  attributed  all  to  the  effect  of  the  Spo- 
rotrichum.  In  1896,  however,  meteorological  condition-  changed, 
and  at  last  the  writer  had  the  good  fortune  to  secure  the  very  oppor- 
tunity for  which  he  had  been  waiting  for  years.  All  through  April 
and  up  to  the  LOth  of  May  in  southern  Ohio  there  was  little  rain,  and 
even  during  the  remainder  of  the  latter  month  the  light  rain-  hardly 
sufficed  to  break  the  drought,  so  that  there  was  a  perfect  breeding 
son  for  the  chinch  bug  during  the  forepart  of  the  breeding  period. 
The  result  was  that  oxer  some  section  g.  7)  there  were  myriads 

of  young  bug-.  Then  the  rain-  came  on.  and  there  were  presented 
the  two  essentia]  requisites  for  success  with  the  fungus,  viz.  chinch 
bugs  and  wet  weather. 

Soon  the  demand-  for  supplies  o!  Sporotrichum  began  to  pour  in. 
and  1,200  package-  wen'  distributed  within  a  few  week-,  instructions 
being  given   to  place  the  content-  of  the  boxes  where  the  chinch  bugs 


PARASITIC    FUNGI.  55 

were  massed  in  greatest  abundance,  giving  preference  to  the  lower 
.iinl  damper  Localit  ies  in  I  he  fields. 

A.fter  the  distribution  had  been  finished,  the  sections  where  the  out- 
break of  chinch  bugs  had  been  the  most  severe  and  where  the  larger 
portionof  the Sporotrichum had  been  distributed  were  visited.  There 
was  certainly  no  mistaking  the  effect  of  the  fungus.  Going  to  the 
place  in  ;i  field  (generally  a  wheal  field)  where  the  fungus  had  been 
introduced,  the  track  of  the  chinch  bugs  a^  they  moved  in  any  direc 
lion  was  in  many  cases  almost  literally  paved  with  the  dead  bugs 
more"  or  less  enveloped  in  their  winding  sheets  of  while  A.long 
ravines,  dead  furrows,  or  other  depressions,  the  ground  would  be 
nearly  white,  the  dead  diminishing  in  numbers  as  the  higher  grounds 
wore  readied,  though  these  wen1  by  no  means  free  from  corpses.  In 
one  instance  the  bugs  had  left  a  field  of  wheal  at  harvest,  the  Spo- 
rotrichum having  been  applied  there  before  the  movement  began, 
and  entered  an  adjoining  cornfield.  The  way  was  marked  with 
white,  not  only  the  surface  of  the  ground,  hut  on  stirring  up  the 
mellow  -oil  of  the  edge  of  the  cornfield  it  was  found  to  he  literally 
full  of  dead  chinch  bugs  to  the  depth  of  2  or  .">  inches,  the  white 
fungus-covered  bodies  strongly  contrasting  with  the  black  color  of 
the  rich  loam.  Xot  only  this,  but  under  the  -heaths  of  the  leaves 
and  on  the  Leaves  themselves  hundreds  of  dead  were  to  be  found  on 
the  outer  rows  of  corn,  on  the  grass  and  weeds,  and.  indeed,  almost 
everywhere.  Millions  of  chinch  bugs  were  certainly  destroyed  in  this 
one  field. 

In  other  fields,  where  the  number  of  bugs  had  been  less,  the  dead 
were  less  numerous,  and  then  they  were  more  apt  to  be  scattered  over 
the  leaves  of  the  corn,  as  in  such  cases  a  diseased  bug  seems  to  be  ani- 
mated with  a  desire  to  crawl  upward  on  any  object  which  presents 
itself,  just  as  a  larva  of  the  clover-leaf  weevil,  Phytonomus  punctatus 
Fab.,  when  attacked  by  Entomophthora  sphcerosperma  (Fres.)  will 
climb  to  the  tip  of  a  vertical  blade  of  grass  and  coil  itself  around  it, 
and.  holding  it  in  the  grasp  of  death,  remain  in  that  position  so 
strongly  attached  that  the  winds  and  rains  fail  to  dislodge  it  until  it 
has  become  disintegrated.  In  other  localities,  where  no  Sporotrichum 
had  been  distributed,  the  ravages  had  certainly  been  greater  and  the 
writer  failed  to  find  any  indication  of  the  presence  of  the  fungus. 
So  far  a-  his  observation  extended,  unless  there  were  a  sufficient 
number  of  chinch  bugs  massed  to  become  injurious,  the  fungus  had 
but  little  effect  upon  them.  In  other  words,  the  massing  appeared 
to  be  an  essential  requisite.  Whether  this  was  sufficient  of  it-elf.  or 
whether  the  effect  of  massing  was  to  reduce  the  vitality  of  the  indi- 
vidual bug.  and  thus  render  it  more  susceptible  to  the  spores  of  the 
fungus,  it   i>  impossible  for  the  writer  to  decide:   but    he  ha-   long 


56  THE    CHINCH    BUG. 

suspected  that  the  latter  was  the  true  solution  of  the  problem.  We 
know  thai  most  domestic  animals  or  fowls  thrive  best  and  are 
the  most  vigorous  when  kept  in  small  flocks,  while  among  humans 
the  maximum  of  health  and  minimum  of  disease  is  obtained  where 
the  individuals  are  scattered  over  a  moderate  area  per  capita  and  the 
atmosphere  is  dry  and  pure:  low,  damp,  and  ill-ventilated  quarters, 
when  overcrowded,  being  especially  fatal,  particularly  to  the  young. 
The  individual  in  perfect  health  and  vigor  may  in  one  sense  be  said 
lo  be  above  and  out  of  reach  of  disease,  and  before  the  two  can  be 
brought  together  there  must  be  some  interacting  element  that  will 
brin^  the  individual  down  to  a  point  where  lie  can  be  reached  by  the 
disease;  that  i>.  the  disease  can  rise  only  to  a  certain  plane  and  the 
ictim  needs  to  be  first  attacked  by  some  element  not  necessarily 
fatal  in  itself,  but  sufficiently  depressing  to  bring  the  individual 
down  to  where  he  can  be  grasped  by  the  disease. 

METEOROLOGICAL     INFLUENCES      FAVORING     DEVELOPMENT     OF     FUNGOUS      KNEMIES     OF 

THE    CHINCH    BUG. 

"When  human  beings  are  overcrowded  and  some  disease  is  intro- 
duced among  them,  everyone  knows  the  effect  of  a  low.  damp  locality 
under  a  high  temperature  and  with  both  air  and  water  more  or  less 
stagnant.  Even  the  once  healthy  and  vigorous  are  more  or  less 
reduced  and  enervated  by  their  environment,  and  thus  brought  within 
the  influence  of  the  deadly  disease.  Again,  if  an  individual  is 
stricken  and  forsakes  his  miasmatic  surroundings  for  those  more 
salubrious,  the  disease  may  still  overcome  him.  but  seldom  spreads 
to  others,  except  such  as  come  in  actual  contact  with  either  himself  or 
his  belongings,  while  if  not  too  much  reduced  before  changing  his 
habitation  the  chances  are  much  more  favorable  for  his  recovery. 

It  seems  to  the  writer  that  ki  this  matter  of  metorological  conditions 
and  their  relation  to  the  effect  of  entomogenous  fungi  on  the  chinch 
bug  we  are  really  dealing  with  the  same  problem  in  a  different  field. 
Idie  young  chinch  bug  which  has  not  yet  come  into  possession  of  its 
full  measure  of  strength,  and  the  spent  females,  which  have  lost  theirs, 
fall  easiest  as  the  prey  to  these  fungi,  while  the  fully  developed  bugs, 
endowed  with  health  and  vigor,  appear  to  be  to  some  extent  immune 
to  the  attacks  of  these  enemies,  and  if  not  massed  in  large  bodies  they 
seem  still  more  likely  to  escape  destruction.  In  the  timothy  meadows 
of  northeastern  Ohio  an  occasional  dead  adult  has  been  found  in  late 
autumn,  but  the  fungus  had  certainly  not  claimed  many  victims, 
though  both  the  long  and  the  short  winged  form-  were  present  in  con- 
siderable  abundance,  clustered  about  the  roots  of  grass.  With  Forbes 
the  writer  believe-  that  after  becoming  fully  matured  the  chinch  bug 
i-.  largely  at  least,  beyond  the  reach  of  Sporotrichum.     What  is  the 


A    BACTERIAL    I'M  .MY    OF    THE    CHINCH     BUG.  57 

element  thai  serves  to  enervate  and  reduce  the  older  larvae  and  pupa 
as  well  as  many  recently  developed  adults  among  them?  I-  there 
nothing  that,  not  of  Itself  fatal,  so  acts  upon  the  system  of  the  bugs 
ihat  they  are  brought  into  a  condition  of  susceptibility  -a  -on  of 
"go-between,"  so  to  -peak,  but  which  demands  atmospheric  moisture 
before  it  will  rise  to  an  aggressive  state? 

A   BACTERIAL  ENEMY  OF  THE  CHINCH   BUG. 

Forbes  finds  that  the  bacterium  Bacillus  insectorum  Burrill  is  nor- 
mal to  the  chinch  bug  and  occurs  always  in  tin1  intestinal  cceca,  and 
the  writer  has  often  wondered  if  this  were  not  the  very  reducing  ele- 
ment. In  a  paper  contributed  to  the  "American  Practitioner,"  Sep- 
tember, L891,  he  describes  the  effect  of  this  bacteria  on  the  cceca  as 
completely  destroying  the  secreting  epithelium,  the  cells  of  which 
break  down  and  disappear,  leaving  the  delicate  tubes  filled  with  a 
vast  mass  of  microbes  with  some  small  intermixture  of  droplets  of 
tat  and  a  little  nondescript  debris,  the  result  of  cellular  decomposi- 
tion. Now,  it  certainly  seems  to  the  writer  that  we  may  here  have  the 
very  enervating  element  necessary  and  which,  in  order  to  become  suffi- 
ciently aggressive  to  perform  its  functions  perfectly,  requires  the 
very  conditions  afforded  by  frequent  showers,  without  which  it  is 
comparatively  helpless.  We  know  very  well  that  human  beings  are 
far  more  susceptible  to  disease  when  weakened  by  fatigue,  dissipa- 
tion, or  other  forms  of  exhaustion,  and  under  such  conditions  suc- 
cumb to  disease  when  they  would  otherwise  enjoy  immunity  there- 
from. We  will  not,  however,  follow  this  further,  but  submit  it  as  a 
problem  well  worthy  of  careful  consideration  and  study.  In  his  own 
experiments  with  Sporotrichum  globuliferum  the  .writer  has  found 
that  under  the  most  favorable  conditions  the  fungus  will  attack  even 
the  youngest  larvae,  while  Forbes  states  that  it  will  also  attack  the 
egg-,  but  in  the  fields  it  seemed  generally  most  prevalent  among  the 
more  advanced  larva',  pupae,  and  newly  developed  adults,  though 
much  depends  upon  meteorological  conditions  and  the  abundance  of 
chinch  bugs,  as  well  as  the  time  during  the  breeding  season  when 
the  fungus  is  doing  its  work.  That  is  to  say,  there  is  a  time  at  the 
beginning  of  the  breeding  season  when  there  are  only  adults  and 
young  larvae;  later  there  will  be  larvae  of  various  ages,  and,  toward 
the  last,  few  if  any  of  these,  but  all  will  be  either  pupae  or  adult-. 
For  some  reason  it  seemed  more  difficult  to  get  the  Sporotrichum  to 
work  satisfactorily  when  the  chinch  bugs  were  beginning  to  breed 
than  later  on.  the  last  of  June  and  the  early  part  of  July.  These 
fact-  are  mentioned  here  to  -how  that,  judging  by  their  effect-,  these 
fungi  hold  a  secondary  place. 


58  THE    (   H  IXC  II    BTC 

THE    PRACTICAL    I  T1I.ITY    OF    I  I    NGOl   -    AND   BACTERIAL    ENEMIES    IN 

FIGH  I  :  \<      I  m:   <  H1NCH    1U  G. 

Regarding  the  practicability  of  utilizing  these  entomogenous  fungi 
in  agriculture,  there  seems  uo  reason  to  revise  a  statement  made  ten 
years  ago,  viz,  thai  this  can  be  done  only  in  cases  of  excessive  abun- 
dance and  during  wet  weather,  the  basis  for  infection  being  provided 
by  some  centra]  propagating  station  from  which  fanner-  can  receive 
promptly  an  abundant  supply.  The  writer  believes  that  for  himself 
be  could  manage  to  get  considerable  benefit  from  their  use  in  destroy- 
ing chinch  bugs,  provided  he  were  Located  within  the  area  of  the  fre- 
quent occurrence.  This  could  be  done  only  by  watching  the  seasons 
carefully,  and  in  case  there  should  occur  two  year-  in  succession 
wherein  the  breeding  period-  were  covered  by  drought,  then  every 
preventive  measure  known  should  be  adopted,  notably  the  burning 
of  leaves,  dead  grass,  and  other  rubbish  during  winter  or  early  spring, 
followed  up  by  -owing  small  plats  of  early  millet,  Hungarian  grass, 
or,  better  yet  perhaps,  spring  wheat,  in  low  damp  places  in  the  fields, 
with  a  view  of  attracting  the  females  or  in  fact  massing  the  bugs, 
and  then  freely  applying  the  fungi  in  their  midst.  "Whether  the 
average  farmer,  with  his  somewhat  crude  ideas  of  entomology,  can  do 
this  successfully  or  not  is  very  uncertain.  It  is  almost  impossible  to 
determine  even  a  few  weeks  in  advance  whether  a  season  i-  to  be  fa- 
vorable or  unfavorable  to  the  development  of  the  chinch  bug,  which 
would  of  itself  cause  occasional  false  alarm,  and  the  precautionary 
measures  rendered  entirely  unnecessary  by  a  few  timely  and  drench- 
ing rain-  just  at  the  critical  time.  Before  we  can  expect  to  be  emi- 
nently successful  in  this  matter,  not  only  the  farmer  but  also  the 
entomologist  and  meteorologist. have  much  to  learn. 

THE    BOB  WHITE    OR    QUAIL. 

Chinch  bug-  have  few  important  enemies  among  the  bird-  of  the 
aorthern  United  Si  ate-.  To  what  extent  the  coast  birds  feed  upon 
them  it  i-  impossible  to  say,  but  inland  the  common  quail  or  bobwhite 
{(  olinus  virginianus)  is  the  only  species  that  can  be  said  to  devour 
any  considerable  number.  As  this  is  one  of  our  most  highly  prized 
game  birds,  it  i-  slaughtered  annually  in  tremendous  number-. 

The  following  list  will  -how  the  degree  of  protection  offered  the 
quail  by  legislative  enactment  in  the  State-  where  the  chinch  bug  i- 
the  most  destructive.  The  close  season  for  quail  in  the  several  State-, 
during  which  killing  i-  prohibited  by  law,  is  as  follow-: 

Maine,  all  the  year. 

New  York.  December   l   to  November  1,  excepl   in  some  counties  whore  it  is 

from  December  l   to  October  16.     in  Rensselaer  County  il   is  from  1 mber  l 

to  October  i  and  iii  Richmond  County  all  the  year  until  1908. 

l  armers'  Bulletin  No.  265,  pp.  13-25,  1906. 


THE    PROG.  59 

Pennsylvania,  December  i  to  November  i. 
Ohio,  Decembers  t<>  November  15. 
Indiana,  January  I  to  November  LO. 
Illinois.  December  20  to  November  10. 
Minnesota,  December  1  to  October  L. 
low.i.  December  15  n>  November  I. 
Missouri,  January  I  i<»  November  1. 
Nebraska,  December  i  i<>  November  15. 

Kansas,  December  l">  to  November  15,  with  some  exceptions  where  the  close 
season  extends  t<>  Marcb  1 1.  1908." 
Oklahoma,  February  i  to  October  15. 
Texas,  February  1  to  November  I. 

The  breeding  season  from  Latitude  38  northward  to  Canada  begins 
in  May.  and  continues  through  July  and  occasionally  into  September 
or  even  October.  A  young  bird  just  from  the  nesl  was  taken  in 
Wayne  County.  Ohio,  September  5,  L887.&  There  arc  probably  two. 
and  southward  three,  broods  each  season,  and,  while  rather  prolific,  the 
quails  are  kepi  well  reduced  in  numbers,  at  times  to  the  verge  of  exter- 
mination over  considerable  sections  of  country.  They  are  hunted 
incessantly  and  slaughtered  without  consideration,  except  for  gain. 
Some  also  are  killed  by  flying  against  electric  wires,  while  entire 
coveys  are  sometimes  smothered  or  frozen  under  the  snow.  As  a 
result,  the  helpfulness  of  the  quail  against  chinch  bugs  is  greatly 
diminished. 

OTHER  BIRD  ENEMIES  OF  THE  CHINCH   BUG. 

Among  the  other  bird  enemies  of  the  chinch  bug  are  the  prairie 
chicken,  redwing  blackbird,  catbird,  brown  thrush,  meadowlark, 
house  wren,  tree  swallow,  and  horned  lark,  but  there  is  little  doubt 
that  in  seasons  when  the  chinch  bug  is  excessively  abundant  the  com- 
paratively few  eaten  by  all  of  these  birds  is  insufficient  to  reduce  the 
number-  of  the  pesl  to  any  extent. 

THE    FROG. 

Dr.  Cyrus  Thomas  quotes  Professor  Ross  and  others  a-  stating  that 
the  common  frog  is  an  enemy  of  the  chine!)  bug.  While  this  is  prob- 
ably true,  it  i-  nevertheless  well  known  that  comparatively  few  Progs 
frequent  grain  fields  as  a  rule,  and  thus  the  bench!  derived  l'i om  their 
attacks  i>  of  too  little  importance  to  merit  further  notice. 

"In  Rawlins  County,  under  restrictions.  November  I  to  January  I. 
''A  preliminary  I.M  of  the  Birds  of  Wayne  County,  Ohio,  by  Harry  C.  Ober 
bolser.     Bui.  Ohio  Agric.  Exp.  Sta.,  Tech.  Ser.,  Vol.  1,  No.  1.  p  270. 


60 


THE    CHINCH    BUG. 


Fig.  lb.—  Triphleps  insidio- 
SUsF&b.     (From  Riley,  i 


INVERTEBRATE    ENEMIES    OF    THE    CHINCH    BUG. 

Of  the  invertebrate  enemies  the  same  may  be  said  as  of  the  frog. 
The  writci-  has  occasionally  found  a  chinch  bug  containing  a  specie- 
of  .Menni-.  "  bail-  snake."  Also  occasionally  ants  may  be  seen  drag- 
ging these  bugs  away,  while  lady-beetles  have  sometimes  been  found 
I-)  devour  them,  a-  recorded  by  Walsh  and  Forbes.  Perhaps  the 
worst  insect  enemies  of  the  chinch  bug  are  to  be 
found  among  its  comparatively  near  relatives, 
the  insidious  flower  bug.  Triphleps  msidiosus 
Say  (Anthocoris  pseudo-chinche  of  Fitch's  Sec- 
ond Report)  (fig.  15),  and  MUyas  ductus  Fab. 
(fig.  16),  the  latter  being  reported  by  Doctor 
Thomas  as  the  most  efficient  of  the  insect  ene- 
mies of  this  pest,  while  Doctor  Riley  found  that 
the  former  also  attacked  it.  Professor  Forbes 
ascertained  by  examinations  of  the  contents  of 
the  stomach  of  a  ground  beetle,  Agonoderus 
pallipes  Fab.,  that  one-fifth  of  the  total  food  of 
this  species  was  composed  of  chinch  bugs.  Doctors  Shimer  and 
Walsh  both  claim  that  lace-wing  flies  (Chrysopa)  destroy  chinch 
bugs,  and  they  are  doubtless  correct.  The  writer  has  also  very  often 
found  dead  chinch  bugs  entangled  in  spider  webs,  though  whether 
killed  for  food  or  by  accident  it  has  been  impossible  to  determine. 
It  will  be  seen,  however,  that  the  combined  influence  of  all  of  the 
natural  enemies  of  the  chinch  bug.  parasitic  fungi  excepted,  is  far 
too  weak  to  offer  any  material  protection  to 
the  agriculturist  against  this  pernicious 
enemy  of  his  crops,  with  nothing  to  promise 
an  improved  condition  of  affairs  in  this 
direct  ion  in  the  future.  There  may  some- 
times appear  hynienopterous  parasites  of 
the  eggs,  but  we  have  as  yet  no  proof  of  the 
existence  of  such  in  this  country,  and  only 
suspect  the  possibility  of  such  a  phenome- 
non because  other  allied  species  have  similar 
enemies,  which  destroy  their  e££s.  jn 
short,  the  immunity  of  the  chinch  bug  from  attacks  of  other  organ- 
isms i-  so  striking  that  it  ha-  attracted  the  attention  of  all  entomolo- 
gists who  have  made  a  study  of  the  species,  and  all  accept  this  as  indi- 
cating that  it  is  an  exotic,  not  originally  belonging  to  our  insect  fauna. 


Fig.  16. — MUyas  ductus  Fab. 
(From  Riley.) 


REMEDIAL  AND  PREVENTIVE  MEASURES. 

The  list  will  include  all  remedial  and  preventive  measures  that  have 
been  found  to  possess  the  merit  of  reasonable  efficiency  and  practica- 
bility.    These  may  not  all  prove  applicable  in  all  localities  or  under 


REMEDIAL    AND    PREVENTIVE    MEASURES.  61 

every  variety  of  circumstance,  and  the  farmer  will  often  have  to  lit 
his  protective  measure  to  meet  weather  conditions,  location  of  field 
ami  its  surroundings,  as  well  as  the  thousand  and  one  other  variations 
of  a  similar  nature. 

DESTRUCTION   OF  CHINCH    BUGS   WHILE   IN    HIBERNATION. 

The  lir>t  effort  that  may  be  made  with  a  view  to  warding  off  an  at- 
tack of  chinch  bugs  is  to  destroy  them  in  their  w  inter  quarters.  This 
can  be  accomplished  by  burning  all  dried  grass,  Leaves,  or  other  rub 

bish  during  winter  or  early  spring.  Forbes  (  First  Report,  p.  -\7 )  and 
Marlatt  (Insect  Life,  VII,  p.  232)  have  cast  some  doubt  upon  the 
statements  to  the  effect  that  the  chinch  bug  hibernates  to  any  great 
extent  among  dried  grass,  leaves,  and  rubbish,  but  the  evidence  is  so 
overwhelmingly  in  favor  of  the  assertions  of  nearly  every  entomologist 
who  has  st tidied  the  insect  in  its  hibernation  to  the  effect  that  it  does 
select  such  places  in  which  to  pass  the  winter  that  there  is  hardly  any 
use  of  raising  the  question  at  all.  A  good  illustration  of  the  fact  that 
large  numbers  of  chinch  bugs  ma}^  be  in  hiding  in  such  places  and 
escape  detection  is  shown  by  the  fact  that  a  quantity  of  dried  Leaves 
from  about  a  vineyard  located  on  a  narrow  neck  of  land  about  a 
quarter  of  a  mile  from  the  Bay  of  Sandusky  on  the  one  side  and  about 
U  miles  from  the  shore  of  Lake  Erie  on  the  opposite  side  wTere  col- 
lected late  in  April  and  brought  to  our  insectary  and  placed  in  a 
breeding  cage.  At  the  time  of  collecting  the  leaves  only  an  occasional 
chinch  bug  was  to  be  observed,  but  under  the  warm  atmosphere  of  the 
insectary  they  began  to  stir  themselves,  and  soon  demonstrated  that 
there  had  been  a  large  number  ensconced  unseen  among  the  dried  and 
curled  dead  grape  leaves.  So  it  is  with  the  matted  grass  along  road- 
sides and  fences,  especially  the  Virginia  wTorm  rail-fence. 

While  it  is  not  possible  to  find  the  hibernated  chinch  bugs  by 
searching,  yet  if  pieces  of  boards  are  laid  clown  on  the  grass  in  early 
spring  the  bugs  will  collect  on  the  under  side  and  may  be  found 
there,  or  they  may  be  discovered  by  the  method  of  collecting  known 
to  entomologists  as  sifting.  The  burning  of  all  such  grass  will  de- 
stroy thousands  of  bugs  in  their  winter  quarters;  but  sometimes  the 
matted  bluegrass  remains  green  in  winter,  or  the  weather  is  not 
sufficiently  dry  to  enable  the  farmer  to  burn  over  such  places.  In 
such  cases  a  flock  of  sheep,  if  given  the  freedom  of  the  fields  during 
winter  and  spring,  will  eat  oif  all  living  vegetation  and  trample  the 
ground  with  their  small  feet,  so  that  not  only  is  all  covering  for  the 
bugs  removed,  but  also  the  bugs  are  trampled  to  death.  The  ease 
with  which  the  narrow  -trip  of  grass  land  along  a  post  and  wire 
fence  can  be  kept  free  of  matted  grass  and  leaves,  as  compared 
with  that  along  a  hedge  or  rail  fence,  indicates  that  there  may  be 


( 12  THE    CHINC II    BUG. 

an  entomological  factor  connected  with  the  modern  fence  that  lias 
been  overlooked,  giving  it.  in  this  respect,  an  advantage  over  the 
more  ancient  form.  Shocks  of  fodder  corn  left  in  the  fields  over 
winter  certainly  afford  protection  for  many  chinch  bugs,  a>  also 
will  coarse  stable  manure  spread  on  the  fields  before  the  chinch  bugs 
have  selected  their  place  of  hibernation  in  the  fall.  In  short,  the  first 
protective  measure  to  be  carried  out  is  a  general  cleaning  up  in  winter 
or  early  spring  either  by  burn  inn  or  pasturing  or  both. 

SOWING  DECOY   PLATS  OF  ATTRA<  TIVE  GRAINS  OB  GRASSES  IN  EARLY  SPRING. 

Judging  from  the  manner  in  which  the  wintered-over  adults  are 
attracted  to  hills  of  young  corn,  wheat  fields,  or  plats  of  panic  grass 
and  foxtail,  it  has  always  seemed  to  the  writer  practicable  to  take  ad- 
vantage of  this  habit  and  sow  small  patches  of  millet,  Hungarian 
grass,  spring  wheat,  or  even  corn,  early  in  the  spring  and  thus  bait 
the  adult-  as  they  come  forth  from  their  places  of  hibernation.  Their 
instincts  will  prompt  them  to  seek  out  the  places  likely  to  afford  the 
most  desirable  food  supply  for  their  progeny,  and  if  an  artificial 
supply  can  be  offered  them  that  will  be  more  attractive  than  that 
furnished  by  nature,  the  bugs  will  certainly  not  overlook  the  fact, 
but  will  take  advantage  of  it  to  congregate  and  deposit  their  eggs 
there,  whereupon  eggs,  young,  and  adults  can.  a  little  later,  be  sum- 
marily  dealt  with  by  plowing  both  bugs  and  their  food  under  and 
harrowing  and  rolling  the  ground  to  keep  the  former  from  crawling 
to  the  surface  and  escaping.  The  writer  has  thoroughly  tested  this 
method  in  a  case  where  the  bugs,  young  and  old.  had  taken  posses- 
sion of  a  plat  of  ueglected  ground  overrun  with  panic  grass  (Panicum 
crus-galli):  which  was  mown  and  promptly  removed  and  the  ground 
plowed,  harrowed,  and  rolled  before  the  bugs  could  escape,  thus 
burying  them  beneath  several  Inches  of  soil  out  of  which  they  were 
unable  to  make  their  way.  and  as  a  consequence  they  were  almost 
totally  annihilated,  hardly  1  per  cent  making  their  escape  to  an 
adjoining  cornfield. 

DIFFICULTY  OF  REACHING  CHINCH    BT  GS   IN    MEADOWS. 

There  is,  however,  some  doubt  in  regard  to  the  practicability  of 
applying  these  measures  in  meadow-.  Meadow  lands  can  be  burned 
over  with  perfect  sa  fety  to  either  the  grass  or  clover,  i  f  done  while  the 
ground  is  frozen,  but  there  i-  danger  of  injury  if  burned  over  in 
spring,  \u\d  it  i>  somewhat  doubtful  if  the  hibernating  chinch  bugs 
would  be  killed  unless  the  surface  of  the  ground  was  heated  to  a 
degree  that  the  grass  and  clover  plants  would  hardly  be  able  to 
withstand. 


REMEDIAL    AND    PREVENTIVE     VfEASl   RES.  63 

Enfested  areas  of  meadow  land  could  be  plowed,  it  is  true;  bill  the 
work  would  have  to  be  done  very  carefully,  else  the  grass  and  stubble 
would  be  left  to  protrude  above  ground  along  each  furrow  and  consti 
tute  so  many  ladders  by  which  the  chinch  bugs  could  easily  craw]  ou1 
and  make  theirescape.  Where  the  ground  will  admit  of  subsoiling,  or 
where  a  "jointer  "  plow  can  be  used,  this  latter  difficulty  can  be  easily 
overcome,  (Jsually,  however,  the  chinch  bug  works  too  irregularly  in 
a  field  to  permit  (A'  plowing  under  infested  areas  without  disfiguring 
it  too  much  for  practical  purposes,  especially  in  the  case  of  meadow-, 
uide—  it  be  where  the  bugs  have  migrated  en  masse  from  an  adjoining 
field,  when  a  narrow  strip  along  the  border  can  often  be  sacrificed  to 
good  advantage.  In  many  instance-  the  heroic  use  of  the  plow  in 
turning  under  a  few  outer  rows  of  corn  would  have  saved  as  many 
acres  from  destruction.  In  the  majority  of  cases  it  is  the  fault  of  the 
fanner  himself  that  these  measures  are  not  effective,  as  he  will  sel- 
dom take  the  trouble  to  burn  the  dead  leaves,  grass,  and  trash  about 
his  premises  at  the  proper  time,  and  when  there  occurs  an  invasion 
y>['  chinch  bugs,  instead  of  resorting  to  heroic  and  energetic  measures 
to  conquer  them  on  a  small  area  he  usually  hesitates  and  delays  in 
order  to  determine  whether  or  not  the  attack  is  to  be  a  serious  one. 
and  by  the  time  he  has  decided  which  it  is  to  be,  the  matter  has  gone 
too  far.  and  the  chinch  hugs  have  taken  possession  of  his  held.  This 
i-  especially  true  in  the  Y\  est.  where  the  bugs  breed  exclusively  in  the 
held-  of  wheat  and  remain  unobserved  until  harvest,  when  they  sud- 
denly and  without  warning  precipitate  themselves  upon  the  growing 
corn  in  adjacent  field-.  In  fighting  the  chinch  bug  promptness  of 
action  i-  about  as  necessary  as  it  i>  in  lighting  fire. 

WATCHFULNESS    NECESSARY    DURING    PROTRACTED    PERIODS    OF   DROUGHT. 

It  has  always  appeared  to  the  writer  a--  though  a  little  watchful- 
ness on  the  part  of  farmer-  during  periods  of  drought  might  enable 
them  to  determine  whether  or  not  chinch  bugs  were  present  in  any 
considerable  numbers  in  their  fields,  in  time  to  interpose  a  -trip  of 
millet  between  the  wheat  and  corn,  to  be  utilized  later  a-  previously 
indicated.  Instances  have  come  under  observation  where,  the  wheat 
field-  being  overgrown  with  panic  grass  and  meadow  foxtail,  the  bugs 
transferred  their  attention  to  these  as  soon  as  the  wheat  was  harvested, 
and  a  prompt  plowing  of  the  ground  would  have  placed  the  depre- 
dators beyond  the  possibility  of  doing  any  serious  injury.  If  the 
weather  at  the  time  i>  hot  and  dry,  a  mower  may  be  run  over  the 
stubble  held-  or  along  the  borders  of  them,  cutting  oil  grass,  weed-. 
and  stubble,  as  the  case  may  be,  leaving  them  to  dry  in  the  hot  sun, 
when,   in   a   few   hour-,   they   will    burn   sufficiently  to  roast  all  bugs 


64  THE    CHINCH    BUG. 

among  them,  and.  while  not  destroying  every  individual,  this  will 
reduce  their  numbers  to  such  an  extent  that  they  will  be  unable  to 
work  any  serious  injury. 

In  case  the  weather  at  the  time  should,  on  the  contrary,  be  wet  and 
rainy,  so  that  it  is  impossible  to  mow  and  burn,  the  prompt  distribu- 
tion of  the  rungus  Sporotrichum  will  prove  of  immense  value:  for  in 
this  case  the  more  the  bugs  are  massed  over  a  limited  area,  the  more 
fatal  will  be  the  effects  of  the  fungus,  and  especially  will  this  prove 
true  if  the  land  is  low  and  inclined  to  be  damp.  This  statement  will 
also  hold  good  with  reference  to  meadow  lands  during  the  breeding 
season,  though  later  the  adults  do  not  appear  to  succumb  to  the 
effects  of  the  fungus  nearly  as  readily,  and  the  writer  has  found  the 
fungus  present  in  spring  among  masses  of  hibernating  individuals, 
with  little  indication  of  its  contagious  nature,  only  an  occasional 
individual  being  attacked. 

I  TILITV    OF    KEROSENE    IN    FIGHTING    CHINCH    BUGS. 

In  fighting  the  chinch  bug  there  is  at  present  no  more  useful  sub- 
stance  than  kerosene,  either  in  the  form  of  an  emulsion  or  undiluted. 
From  its  penetrating  nature,  prompt  action,  and  fatal  effects  on  the 
chinch  bug,  even  when  applied  as  an  emulsion,  it  becomes  an  inex- 
pensive insecticide,  while  it  has  the  further  advantage  of  being  an 
article  of  universal  use  in  every  farmhouse,  and  is  therefore  always  at 
hand  for  immediate  use.  The  emulsion  has  the  further  advantage  of 
being  capable  of  sufficient  reduction  in  strength  to  prove  fatal  to  insect 
life  and  yet  not  injure  the  vegetation  upon  which  such -may  be  depre- 
dating. Diluted  and  ready  for  use,  the  emulsion  is  prepared  as  fol- 
lows:  Dissolve  one-half  pound  of  hard  soap  in  1  gallon  of  water. 
preferably  rain  water,  heated  to  the  boiling  point  over  a  brisk  fire,  and 
pour  this  suds  while  still  hot  into  2  gallons  of  kerosene.  Churn  or 
otherwise  agitate  this  mixture  for  a  few  minutes  until  it  becomes  of  a 
cream-like  consistency  and,  on  cooling,  will  form  a  jelly-like  mass 
which  adheres  t<»  the  surface  of  glass  without  oiliness.  For  each  gallon 
of  this  emulsion  use  15  gallons  of  water,  mixing  thoroughly.  If 
applied  to  growing  corn  it  will  be  best  to  use  the  emulsion  either  dur- 
ing the  morning  or  evening,  say  before  8  a.  m.  or  after  5  p.  m.,  as  at 
those  times  it  will  be  less  likely  to  affect  the  plants  than  if  applied 
in  tin'  heat  of  the  day. 

Where  an  invasion  of  the  chinch  bug  is  in  progress  from  a  field  of 
wheat  t<»  an  adjoining  field  of  coin,  a-  an  illustration,  the  marginal 
row-  of  emu  can  frequently  be  saved,  even  after  the  bugs  have  massed 
upon  the  plants,  by  -praying  or  sprinkling  them  freely  with  kerosene 
emulsion,  being  careful  not  to  get  much  of  it  directly  into  the  crown 
of  the  plant-  and  using  a  sufficient  quantity  so  that  the  emulsion  will 


REMEDIAL    AND    PREVENTIVE    MEASURES.  65 

run  down  the  outside  and  reach  such  bugs  as  arc  about  the  base  of 
the  plants.    This  treatment  will  kill  the  bugs  clustered  upon  the  corn, 

and  in  case  of  those  on  the  way  to  the  field,  while  it  will  not  keep 
them  out,  it  will  cause  a  halt  in  the  invasion,  and  thus  give  the 
farmer  an  opportunity  to  put  other  measures  in  operation,  one  of 
which  will  include  the  use  of  kerosene  in  another  manner.  If  a  deep 
furrow  is  plowed  along  the  edge  of  (lie  field,  running  the  land-side 
of  the  plow  toward  the  field  to  he  protected,  the  furrow  will  form  a 
temporary  harrier  to  the  incoming  hordes. 

UTILITY    OF    DEEPLY     PLOWED    FURROWS    SUPPLEMENTED    BY    THE    USE    OF 

KEROSENE    EMULSION. 

In  dry  weather  the  sides  of  this  furrow  can  be  made  so  steep  and  the 
soil  so  finely  pulverized  that  when  the  chinch  bugs  attempt  to  crawl 

up  out  of  the  furrow  they  will  continually  roll  back  to  the  bottom, 
where  they  can  he  sprinkled  with  either  kerosene  alone  or  with  the 
much  Less  expensive  emulsion,  and  killed.  In  case  of  showery  weather, 
which  prevents  the  sides  of  the  furrow  from  remaining  loose  and  dry, 
the  bottom  can  he  cleared  out  with  a  shovel,  making  it  more  smooth 
and  the  sides  more  perpendicular,  thus  rendering  it  so  much  easier  to 
follow  along  the  bottom  than  to  attempt  to  climb  the  sides.  If  holes 
are  (\\\<z  across  the  bottom  at  distances  of,  say,  30  or  40  feet,  the  bugs 
will  fall  into  them  and  can  he1  still  more  easily  disposed  of  by  the  use 
of  kerosene.  That  both  of  these  measures  are  thoroughly  practicable 
the  writer  has  ample  personal  experience  in  evidence,  and  knows  that 
under  most  conditions  that  are  likely  to  obtain,  prompt  and  efficient 
application  is  all  that  is  necessary.  During  a  few  days  this  work 
w  ill  demand  the  closest  watching  and  application,  but  fields  of  grain 
can  he  protected  thoroughly  and  effectually  if  these  measures  are 
faithfully  carried  out.  and  the  expense  of  time  and  money  will  be 
found  to  he  less  than  in  almost  any  other  plan  that  has  been  up  to 
this  time  discovered.  In  his  own  experience,  in  no  case  has  a  field 
attacked  by  a  migrating  army  of  chinch  bugs  come  under  the  writer's 
observation,  but  that  might  have  been  saved  from  very  serious  injury 
by  the  prompt  use  of  either  of  these  measures,  though  under  some 
condition-  the  farmer  might  find  it  advantageous  to  apply  some  of 
the  other  method-  of  protection  here  given. 

THE    81   RFACE    AM)    COAL-TAR    METHOD. 

The  objections  made  by  farmers  to  the  use  of  most  forms  of  these 
barrier-  is  that  the  finest  pulverized  soil  soon  becomes  incrusted  by 
even  the  slightest  rainfall  and  the  hug-  then  pass  over  it  without 
difficulty,  while  harrier-  of  hoards  are  expensive.  J 

26608— No.  69—07  m 5 


66  THE    CHINCH    BUG. 

It  is  feasible  to  eliminate  both  by  simply  smoothing  off  a  path 
along  the  margin  of  an  infested  field  where  such  a  one  adjoins  the  one 
to  lx'  protected.  This  can  be  done  with  a  sharp  hoe,  and  as  the 
margins  of  wheat  fields  usually  become  compacted  it  is  but  little  trou- 
ble to  thus  clear  off  a  path  a  foot  or  more  in  width,  smooth  as  a  floor, 
with  the  surface  almost  as  hard.  In  the  midst  of  this  path  post  holes 
arc  -unk  a-  in  the  bottoms  of  furrows,  and  a  train  of  coal  tar  is  run 
between  them,  being  so  arranged  that  it  will  reach  the  post  hole  near 
the  inner  side  opposite  the  field  from  which  the  bugs  are  migrating. 
In  this  way  as  the  bugs  reach  the  train  of  coal  tar  they  will  follow 
along  until  they  reach  the  post  hole,  while  those  meeting  with  the 
post  holes  will  usually  divide  and,  following  around  it,  join  with  the 
flow  of  bugs  moving  along  the  train  of  coal  tar.  The  result  is  that 
they  become  congested  in  the  acute  angle  where  the  coal-tar  train  i- 
intercepted  by  the  post  holes.  Those  in  the  apex  of  this  angle  can 
not  turn  back,  and  thus  are  continually  pushed  into  the  post  hole>  by 
those  behind.  As  the  bugs,  varying  from  the  red  larva?  to  the 
almost  black  pupae,  mass  along  the  line  of  coal  tar  tluyy  have  much  the 
appearance  of  a  reddish-brown  stream  running  into  the  holes.  From 
these  holes  there  is  no  escape  and  here  the  bugs  can  be  readily  killed 
by  sprinkling  with  kerosene.  The  slightest  train  of  coal  tar  is  suffi- 
cient to  obstruct  the  passage  of  the  bugs,  and  light  rains  will  not 
affect  its  efficiency.  In  dry  weather  these  trains  of  coal  tar  soon  be- 
come covered  over  with  dust  and  must  be  renewed:  but  in  showery 
weather  there  is  no  dust,  and  if  the  coal  tar  is  renewed  daily  or,  at 
most,  twice  each  day  it  will  accomplish  its  work  and  nothing  further 
will  be  needed  than  to  kill  the  bugs  that  have  collected  in  the  post 
holes.  This  measure  is  inexpensive  and  can  be  promptly  put  into 
operation  if  the  coal  tar  is  at  hand.  The  writer  has  been  able  in  this 
way  to  effectively  protect  a  field  of  corn  surrounded  on  two  sides  by 
a  wheat  field  literally  overrun  with  chinch  bugs  at  harvest  and  during 
a  time  when  light  showers  were  occurring,  frequently  several  time- 
each  day. 

THE    RIDGE    AND    COAL-TAB    METHOD. 

Differing  qtiite  materially  from  the  preceding  are  the  various  com- 
binations of  coal  tar  and  ridges  of  earth,  smoothed  and  packed  along 
the  apex,  or,  instead  of  the  ridge  of  earth,  6-inch  boards,  Mich  as 
are  ordinarily  used  for  fencing,  placed  on  edge  and  the  upper  edge 
coated  with  tar.  Forbes  has  reported  excellent  results  from  the  ap- 
plication of  a  line  of  coal  tar  put  directly  upon  the  bare  ground  where 
i  In1  surface  ha-  been  rendered  compact  by  a  recent  fall  of  rain.  Even 
in  this  series  of  protective  measures  kerosene  can  be  used  to  great 
advantage.  In  the  experiment  recorded  by  Professor  Forbes  the  coal 
tar  was  put   upon  the  ground  between  a  wheat  field  and  a  cornfield 


REMEDIAL    AND    PREVENTIVE    MEASUBES.  67 

from  mi  ordinary  garden  sprinkling  pof  from  which  the  sprinkler 
had  been  removed  and  the  orifice  of  the  spout  reduced  in  size  with  a 
plug  of  wood  until  the  tar  came  out  in  a  stream  about  the  size  of  the 
little  finger  and  made  a  line  on  the  surface  of  the  ground  about  three- 
fourths  of  an  inch  in  width.  Post  holes  were  sunk  along  the  line 
from  10  to  '20  feel  apart  on  the  side  next  to  the  wheal  field,  thus  prac- 
tically completing  the  barrier,  and  the  chinch  bugs  being  unable  to 
cross  the  line  of  tar  accumulated  in  the  post  holes  in  vast  numbers, 
where  they  were  killed;  and  those  bugs  that  had  already  entered  the 
cornfield  before  the  barrier  was  constructed  were  prevented  from 
spreading  farther  by  tar  lines  between  the  rows  of  corn,  the  infested 
corn  itself  being  cleared  of  bugs  by  the  application  of  kerosene  emul- 
sion. The  same  writer  states"  that  several  farmers  in  Vermilion 
County.  111.,  prepared  for  the  coal-tar  line  by  hitching  a  team  to  a 
heavy  plank  and  running  this,  weighted  down  with  three  or  four 
men.  over  tin1  ground  once  or  twice  until  a  smooth,  hard  surface  had 
thus  been  made  to  receive  the  tar.  If  the  barrier  was  to  be  made  in 
sod,  a  furrow  was  plowed  and  the  bottom  of  this  made  smooth  by 
dragging  the  plank  along  the  bottom.  In  both  cases  post  holes  were 
sunk  along  the  tar  lines,  and  in  these  were  placed  cans  or  jars  into 
which  the  bugs  fell  in  myriads  and  were  destroyed. 

On  one  farm  of  250  acres  a  coal-tar  line  90  rods  in  length  was  re- 
newed once  each  day  and  killed  about  8  gallons  of  chinch  bugs.  In 
the  case  of  another  farmer  there  were  300  rods  of  tar  lines  with  post 
holes,  cans,  etc.,  which  resulted  in  destroying  about  10  bushels  of 
chinch  bugs.  A  G-gallon  jarful  was  destroyed  in  less  than  half  a  day 
at  one  point  on  the  line.  In  this  last  instance  the  lines  of  tar  were 
renewed  three  times  a  day.  but  even  then  less  than  a  barrel  of  tar 
was  used.  Still  another  farmer,  with  120  rods  of  tar  line,  used  about 
a  third  of  a  barrel  of  tar  and  did  not  lose  a  hill  of  corn;  he  caught 
chinch  bugs  by  the  bushel.  In  some  of  the  cases  cited  the  tar  line 
was  run  in  a  zigzag  course,  the  post  holes  being  situated  at  the  angles, 
and  in  others  leader  tar  lines  were  run  obliquely  to  the  main  tar  line, 
one  end  terminating  at  the  traphole,  but  both  of  these  plans  were 
afterwards  regarded  as  unnecessary,  a  single  straight  line  being  en- 
tirely sufficient  and  less  expensive.  The  numerous  cases  where  these 
methods  were  put  into  execution  with  entire  success  and  at  small 
expense  is  the  best  possible  proof  of  their  practical  utility.  If 
a  farmer  is  situated  near  town,  where  refuse  tin  cans  are  dumped  in 
any  locality  where  they  can  be  got  out  of  the  way,  he  can  select  the 
larger  of  these,  set  them  in  the  post  holes  and  partly  fill  them  with 
kerosene  and  water.  The  water  being  heavier  than  the  kerosene  will 
sink  to  the  bottom,  leaving  a  stratum  of  kerosene  on  the  surface. 

a  Twentieth  Report  of  State  Entomologist  of  Illinois,  p.  39,  1898. 


I')S  THE    CHINCH    BUG. 

The  chinch  bugs  falling  into  this  will  be  forced  down  by  the  weight 
of  those  coming  after,  and  thus  all  will  be  passed  through  the  kero- 
sene into  the  water  below.  This  will  obviate  the  necessity  of  fre- 
quently emptying  the  cans  or  treating  their  contents.  It  may  also 
be  stated  that  where  the  post  hole-  are  quite  deep  and  enlarged  at 
the  bottom  the  bugs  falling  into  them  will  perish  without  further 
attention. 

OTHEK    BARRIES    METHODS. 

Professor  Snow,  working  in  Kansas,  followed  a  somewhat  different 
method  and  one  that,  under  certain  conditions,  might  be  found  supe- 
rior to  that  used  by  Professor  Forbes,  or  the  furrow  and  kerosene 
method  applied  by  the  writer  in  Ohio.  This  modification  consists  in 
throwing  up  a  double  furrow,  known  among  farmer-  as  "  back  fur- 
rowing," and  thus  forming  a  ridge,  the  top  of  which  is  smoothed 
and  packed  with  a  drag  having  a  concave  bottom  of  the  form  of  the 
ridge  to  be  made.  If  the  bottom  of  this  drag  is  covered  with  zinc  it 
will  be  found  to  keep  bright  and  polished  and  by  this  mean-  make 
a  smoother  ridge.  The  substances  used  were  coal  tar  a-  it  came 
from  the  gas  works  and  crude  petroleum  as  taken  from  the  oil  wells. 
The  former  is  the  more  easily  obtained,  except  in  certain  localities, 
and  will  probably  be  found  the  more  practical,  as  it  stands  on  the 
surface  better  and  is  not  so  readily  washed  away  by  rains.  Both  of 
these  substances  are,  however,  offensive  to  the  bugs,  and  they  will 
seldom  attempt  to  cross  them  or  even  come  close  enough  to  touch 
them,  but  on  approaching  will  turn  and  run  along  the  ridge  in  the 
evident  hope  of  finding  a  gap  through  which  they  can  pass.  Post 
holes  were  dug  on  the  outside  of  the  line,  but  close  up  to  it.  so  that 
the  bugs  in  passing  along  beside  the  tar  line  would  crowd  each  other 
into  them.  Professor  Snow  suggests  that  it  will  be  better  to  con- 
struct this  barrier  several  weeks  prior  to  its  being  needed,  as  then  the 
tar  line  has  but  to  be  run  along  the  ridge  and  the  post  holes  dug.  when 
the  whole  system  is  complete  and  the  chinch  bugs  can  be  thus  -hut 
out   from  the  first/' 

With  these  barriers  of  either  ridge  or  furrow  and  the  use  of  coal 
tar  or  crude  petroleum,  supplemented  by  kerosene  emulsion,  a  very 
Large  percentage  of  the  injury  from  chinch  bugs  may  be  prevented, 
and.  in  fact,  with  a  reasonable  degree  of  watchfulness  and  prompt  ac- 
tion, all  injury  from  migrating  hordes  may  be  prevented.  The  use  of 
tarred  boards  set  on  edge  or  -lightly  reclining  might,  under  some 
circumstances,  take  the  place  of  the  ridge  or  furrow,  but  these  cases 
will  be  exceptional,  and  the  use  of  kerosene  emulsion  will  probably 

«  Fifth  annual  Report  of  the  Director  of  the  Experimental  station  of  the  I'ni- 
versity  of  Kansas,  for  the  year  1895  I  1896),  pp.  4-V4T. 


REMEDIAL    AND    PREVENTIVE    MEASURES.  (><) 

be  found  equally  practicable  here,  as  also  will  the  post  holes  for  col 
lecting  the  chinch  bugs.  This  method  is  merely  cited  in  order  to  call 
attention  to  its  possible  use  where  the  others  are  found  impracticable. 
The  plowing  of  furrow-  has  .been  in  vogue  since  the  first  writings  oi 
Le  Baron  and  the  second  report  of  Doctor  Fitch,  and  may  be  utilized 
in  other  ways  than  those  previously  mentioned.  A  heavy  log 
dragged  hack  and  forth  in  this  furrow  will  pulverize  the  soil  in  dry 
weather,  and  Forbes  has  recorded  the  fact  that  where  this  has  a 
temperature  of  1  lo  to  L16  F.  it  is  fatal  to  the  young  bugs  thai  fall 
into  the  furrow,  even  if  they  an4  not  killed  by  the  log.  As  L20  is 
not  uncommon  in  an  exposed  furrow  on  a  hot  summer  day,  it  will  he 
observed  that  there  may  he  eases  where  this  method  will  he  found 
very  serviceable,  and  especially  is  this  likely  to  prove  true  in  a  sandy 
-oil  with  a  southern  exposure.  In  sections  of  the  country  where 
irrigation  is  practiced  these  furrows  may  be  flooded  and  in  this  way 
rendered  -till  more  effective  without  the  expenditure  of  either  time 
of  money  to  keep  them  in  constant  repair.  Doctor  Riley  long-  ago 
laid  considerable  stress  on  this  measure,  believing  it  of  much  value, 
especially  in  the  arid  regions  of  the  far  AYest.  The  same  writer  ad- 
vised the  Hooding  of  infested  fields,  wTherever  it  could  be  done,  for  a 
day  or  so  occasionally  during  the  month  of  May.  It  is  hardly  prob- 
able, however,  that  this  will  often  be  found  feasible  except  in  rice 
Held-,  where  it  is  sometimes  practiced. 

NECESSITY    FOR    PREVENTING  CHINCH  BUGS  FROM  BECOMING  ESTABLISHED 
IN    FIELDS    OF    WHEAT    AND    GRASS. 

In  the  foregoing  it  will  be  observed  that  prevention  of  migration 
has  been  the  chief  vnd  in  view  either  by  destroying  the  chinch  bugs 
in  their  hibernating  quarters,  and  thus  preventing  the  spring  migra- 
tion to  the  breeding  places,  or  by  various  traps  and  obstructions  to 
prevent  them  from  migrating  from  such  places  to  others  not  already 
in  tested.  The  great  problem  remaining  to  be  solved  is  to  prevent  their 
bleeding  in  wheat  fields  at  all.  As  has  been  shown,  it  is  absolutely 
impossible,  with  our  present  inability  to  forecast  the  weather  months 
in  advance,  to  be  able  to  foretell  whether  or  not  an  outbreak  of  chinch 
bug-  is  likely  to  take  place.  There  may  be  an  abundance  of  bugs  in 
the  fall  -enough  to  cause  an  outbreak  over  a  wide  section  of  coun- 
try -and  these  may  winter  oxer  in  sufficient  numbers  to  cause  some 
injury  in  spring,  yet  a  few  timely,  drenching  rains  will  outbalance  all 
of  the-«'  factors,  and  our  wisest  prognostications  fail  of  proving  true. 
It  i<  this  very  factor  of  uncertainty  that  renders  unlikely  the  success- 
ful carrying  out.  over  any  large  area  of  country,  of  any  protective 
measures  where,  as  in  this  case,  the  benefit  to  be  derived  will  only  be 
realized    nearly  a   year  afterwards,  if  at   all.     The  average   farmer, 


70  THE    CHINCH    BUG. 

when  smarting  under  a  heavy  loss,  will  often  take  such  long-range 
precautions  as  to  sow  belts  of  flax,  hemp,  clover,  or  buckwheat  around 
his  wheat  field  once;  hut  if  the  chinch  bugs  do  not  appear,  and  he  sees 
the  useless  investment  of  time,  labor,  and  seed,  he  will  be  likely  to  con- 
clude next  year  to  take  the  risk  and  do  nothing.  For  the  present,  then, 
we  have  no  method  whereby  Ave  can  prevent  the  chinch  bugs  from 
taking  up  their  abode  in  wheat  fields  or  timothy  meadows  and 
raising  their  enormous  families  there,  except  to  destroy  the  adults 
in  their  winter  quarters. 

The  writer  once  tried  to  destroy  the  young  in  a  wheat  held  by 
spraying  with  kerosene  emulsion  the  small  areas  of  whitening  grain 
that  indicated  where  the  pests  were  massed  in  greatest  abundance. 
The  result  was  unsatisfactory,  and  it  is  very  doubtful  if  it  is  possible 
to  apply  this  measure  with  any  degree  of  success,  and  we  are  forced 
to  the  conclusion  that,  for  the  present  at  least,  we  shall  be  obliged 
to  rely  upon  the  measures  previously  given.  It  therefore  becomes 
of  the  utmost  importance  to  clean  up  the  roadsides,  and  along  fence's 
and  patches  of  Avoodland,  as  well  as  any  other  places  likely  to  afford 
protection  for  the  hibernating  chinch  bugs.  There  are  of  course 
obstacles  in  the  way  of  carrying  out  this  plan  generally  over  any 
large  area  of  country,  and  especially  in  sections  where  the  rail  fence 
predominates.  But  as  the  country  gets  older  it  will  be  found  that 
it  is  not  chinch  bugs  alone  that  seek  these  places  in  which  to  pass 
the  winter,  but  myriads  of  the  other  insect  foes  of  the  farmer  as 
well,  and  that  careful  attention  to  the  condition  of  roadsides,  lanes, 
hedgerows,  and  waste  places  about  the  farms,  during  the  season 
when  insects  seek  out  these  places  wherein  to  pass  the  winter,  will 
pay  well  for  the  time  expended  in  that  direction.  It  may  come 
about  that  some  phase  of  the  street-cleaning  reform  may  invade  the 
country,  and  it  is  certain  that  if  such  were  to  occur  it  would,  in  time. 
save  the  country  enough  to  go  far  toward  reducing  the  expense  of 
securing  good  roads.  In  fact,  the  term  "  good  roads "  ought  to 
include  the  proper  care  of  the  roadsides,  as  well  as  the  grading  and 
macadamizing  of  the  roadbed  itself. 

There  are  at  present  so-called  weed  laws  in  many  States,  and. 
though  more  or  less  of  a  dead  letter  in  most  cases,  these  laws  are 
steps  in  the  proper  direction.  The  time  when  insect  pests  will  be 
looked  upon  in  the  eye  of  the  law  as  so  many  public  nuisances,  and 
the  harboring  of  them  a  corresponding  crime,  may  be  a  long  way  off, 
but  as  it  gradually  draws  nearer  to  us  Ave  shall  conic  to  learn  that, 
after  all,  it  is  the  rational  vieAv  to  take  and  will  go  far  toward  solv- 
ing not  only  the  chinch  bug  problem,  but  many  others  of  a  similar 
nature.  So  far  as  the  chinch  bug  is  concerned,  when  Ave  burn  OATer 
the  Avaste  lands  and  accumulated  rubbish  about  our  farms  in  autumn 
or  winter,  Ave  are  simply  applying  the  same  check  that  the  dusky 


RKMKD1.U.    AND    I'KKVHXTIVE    MEASURES.  71 

savage  did  when  he  Lighted  the  prairie  fires,  though  unwittingly  and 
for  an  entirely  different   purpose.     In  t ho  timothy  meadows  of  the 

northeastern  portion  of  the  country,  where,  for  lack  of  wings  fitted 
for  locomotion,  the  chinch  bug  does  not  so  largely  migrate  to  the 
waste  lands  in  autumn,  the  problem  is  somewhat  different,  and  it  will 
require  some  careful  experiments  to  determine  the  exact  effects  of 
burning  over  the  meadow  lands  in  winter,  both  on  the  hibernating 
chinch  bugs  and  on  the  grass  foots.  There  can  be  little  doubt,  how- 
ever, that  a  rapid  rotation  of  crops,  so  as  not  to  allow  the  short- 
winded  form  to  become  thoroughly  established  in  a  meadow,  and  the 
burning  over  of  waste  places,  thus  destroying  such  rubbish  and 
debris  as  will  serve  to  offer  hibernating  places  for  the  long-winged 
form,  will  go  far  toward  settling  the  chinch  bug  problem  in  grass 
lands. 

As  previously  stated,  the  chief  drawback  in  putting  preventive 
measures  in  force  is  in  the  difficulty  of  foretelling  an  invasion.  In 
northeastern  Ohio  in  1897  hundreds  of  acres  of  timothy  meadow 
were  destroyed  after  the  hay  crop  had  been  removed,  but  so  late  that 
the  farmers  did  not  suspect  the  true  condition  of  their  meadows  until 
the  spring  of  1898,  when  the  young  grass  failed  to  put  forth  and  an 
examination  revealed  the  fact  that  the  roots  had  been  killed,  the 
abundance  of  chinch  bugs  pointing  unerringly  to  the  cause  of  the 
trouble,  though  in  many  cases  a  heavy  crop  of  hay  had  been  removed 
the  previous  year  where  now  the  ground  was  entirely  bare.  While 
in  the  case  just  cited  a  previous  knowledge  of  the  presence  of  chinch 
bugs  in  these  meadows  might  not  have  enabled  the  owners  to  have 
saved  them  in  the  fall  of  1897,  yet  the  fall  plowing  of  the  land,  possi- 
bly early  enough  to  have  sown  the  ground  to  fall  wheat,  would  have 
buried  the  majority  of  the  bugs  so  deeply  in  the  soil  as  to  have  killed 
vast  numbers  of  them  and  thus  prevented  their  migrating  to  other 
lands  in  the  spring  of  1898.  A  rotation  of  crops  that  would  have  in- 
cluded grass  for  not  to  exceed  two  successive  years,  followed  by  wheat, 
would  have  amounted  to  precisely  the  same  remedial  measure  as  the 
one  suggested. 

A  case  in  northeastern  Ohio  has  come  to  the  writer's  notice  where 
an  infested  timothy  meadow  was  plowed  late  in  the  fall  of  1897. 
Late  in  April  of  1898  this  ground  was  cultivated,  rolled,  and  har- 
rowed several  times  and  most  carefully  and  completely  prepared  for 
corn,  which  was  planted,  but  with  the  result  that  a  portion  of  the  field 
was  attacked  and  destroyed  by  chinch  bugs,  largely  of  the  brachypter- 
ous  or  short-winged  form.  An  examination  about  June  10  revealed 
the  bugs  in  considerable  numbers  about  the  still  remaining  plants,  but 
scattered  over  the  field  were  more  or  less  numerous  clumps  of  timothy, 
in  some  cases  apparently  having  been  killed  by  the  chinch  bugs,  while 
in  others  these  were  literally  swarming  about  the  dying  but  still 


72  THE    CHINCH    BUG. 

green  clumps  of  grass,  thus  showing  that  the  former  had  either  not 
been  buried  by  the  plowing  and  cultivation  of  the  ground,  or  else  the 
grass  had  not  been  thoroughly  covered,  and  thus  ladders  had  been  left 
whereby  they  were  enabled  to  climb  to  the  surface. 

SUMMARY    OF    REMEDIAL    AND    PREVENTIVE    MEASURES. 

In  summing  up  the  matter  of  remedial  and  preventive  measures 
for  the  control  of  the  chinch  bug.  it  may  be  stated  that  the  insects  can 
be  destroyed  in  their  places  of  hibernation  by  the  use  of  fire.  They 
can,  under  favorable  meteorological  conditions,  be  destroyed  in  the 
fields,  if  present  in  sufficient  abundance  during  the  breeding  season, 
by  the  use  of  the  fungus  Sporotrichum  globuliferum,  if  promptly  and 
carefully  applied.  They  can  be  destroyed  while  in  the  act  of  migrat- 
ing from  one  field  to  another  by  tarred  barriers  or  deep  furrows  sup- 
plemented by  post  holes,  and  by  being  buried  under  the  surface  of  the 
ground  with  the  plow  and  harrow;  or  the  latter  method  can  be  ap- 
plied after  the  bugs  have  been  massed  upon  plats  of  some  kind  of 
A'egetation  for  which  the  bugs  are  known  to  have  a  special  fondness, 
which  decoys  should  be  so  arranged  as  to  either  attract  the  females 
and  induce  them  to  oviposit  therein,  or  they  should  be  arranged  with 
the  idea  of  intercepting  an  invasion  from  wheat  fields  into  cornfields. 
"When  these  decoys  have  been  turned  under  with  a  plow  and  the  sur- 
face immediately  smoothed  and  packed  by  harrow  and  roller,  the  bugs 
will  be  destroyed.  While  in  the  cornfields  they  can  be  destroyed  on 
the  plants  by  the  application  of  kerosene  emulsion.  Without  vigi- 
lance and  prompt  action,  however,  only  indifferent  results  are  to  be 
expected  from  any  of  these  measures. 

PROBABLE  ORIGIN  AND  DIFFUSION  OF  THE  CHINCH  BUG. 

For  the  farmer  engaged  in  attempts  to  check  the  ravages  of  the 
insect  in  his  fields  the  question  of  origin,  or  how  it  came  to  reach 
him,  will  at  the  time  have  little  interest  for  him.  It  will  suffice  that 
it  is  present  in  overwhelming  numbers,  and  what  he  will  most  desire 
will  be  to  learn  how  to  rid  his  premises  of  its  most  unwelcome 
presence  in  the  most  summary  manner  possible. 

If,  however,  the  farmer  happens  to  be  a  thoughtful  and  observing 
man  he  will  sometimes  wonder  how  it  is  that,  except  in  Virginia  and 
the  Carolinas,  a  person  need  not  be  very  aged  in  order  to  remember 
a  time  when  the  chinch  bug  was  an  unknown  factor  in  his  profession, 
with  a  possible  value  far  too  small  to  merit  consideration.  If  he 
happens  to  reside  in  northeastern  Ohio  or  in  some  portions  of  Xew 
York,  and  has  -pent  some  time  in  Illinois.  Iowa.  Kansas,  or  Minne- 
sota, he  will  probably  marvel  at  the  striking  difference  in  appearance 


PROBABLE   ORIGIN    and    DIFFUSION.  ,  3 

between  many  of  the  chinch  bugs  of  his  own  locality  and  those  found 
in  any  of  the  last-mentioned  States,  and  will  probably  be  able  to 
satisfy  himself  of  their  identity  only  by  the  similarity  of  their  vile 
odor.  Again,  he  will  probably  be  equally  at  a  loss  to  understand 
why  it  is  that  his  own  timothy  meadows  are  overrun  by  these  pestifer 
ons  insects  and  destroyed,  while  in  other  Localities,  perhaps  less  than 
1(H)  miles  away,  similar  meadows  are  lefl  untouched,  the  injury 
there  being  confined  to  the  wheat  and  corn  fields. 

If  wondering  leads  to  questioning,  as  it  often  docs  among  the 
constantly  increasing  number  of  educated  and  up-to-date1  farmers, 
it  will  not  satisfy  him  to  receive  an  evasive  or  obscure  reply  to  his 
query  as  to  why  such  differences  exist,  for  if  he  can  not  get  a  clear 
explanation  he  will  want  ideas,  theories,  or  possibilities.  lie  wants 
the  hot  explanation  possible  to  give  until  some  one  finds  out  a  better 
one.  realizing  that  had  mankind  been  perfectly  satisfied  with  the 
knowledge  that  a  stroke  of  lightning  would  split  a,  tree  or  destroy 
human  life,  and  had  stubbornly  refused  to  listen  to  possibilities  or 
to  anything  hut  facts,  we  would  not  now  he  able  to  understand  and 
utilize  electricity  in  the  many  ways  that  we  do  at  the  present  time. 
Such  men  understand  perfectly  that  the  solution  of  most  problems 
in  natural  science  must  of  necessity  commence  with  theories  which 
musl  he  patiently  tested  and  adopted  or  rejected  as  the  results 
demand,  while  the1  scientific  man  knows  that  the  solution  of  one 
problem  often  opens  up  the  way  for  the  solution  of  another,  the 
last  not  infrequently  having  an  entirely  different  application  from 
the  first. 

The  science  of  applied  entomology  is  growing  rapidly  and  becoming 
both  broader  and  deeper,  and  it  is  not  enough  simply  to  tell  the  hus- 
bandman what  an  insect  is  and  how  to  kill  it.  He  must  have  some- 
thing along  with  that  information  to  set  his  own  mind  to  thinking,  to 
work  out  problems  or  improve  upon  the  solutions  already  given  him, 
otherwise  it  is  much  like  giving  money  to  a  professional  beggar.  If 
we  can  not  give  facts  based  upon  demonstrations,  then  give  the  best 
explanation  possible,  even  though  it  he  a  theory  which  is  only  ex- 
pected to  stand  until  some  one  does  better.  It  is  for  the  thoughtful, 
progressive  farmer,  as  well  as  the  -indent  of  geographical  distribu- 
tion, that  this  possible  solution  of  the  problem  of  the  chinch  hug  has 
been  prepared,  and  while  the  full  practical  value  of  the  ideas  ad- 
vanced ha-  yet  to  \w  demonstrated,  this  of  it-elf  can  not  he  wv^nl  as 
sufficient  grounds  for  not  -ending  it  forth  for  study  and  consideration. 

Thanks  to  the  careful  observations  of  Professor  Sajo,  on  the  Euro- 
pean species  of  chinch  bug.  Blissus  dorice^  it  is  \u<\\  for  the  first  time 
possible  to  compare  the  habits  of  tin-  species  with  our  own. 


74  THE    CHINCH    BUG. 

INDICATIONS  OF  A    PROBABLE   DISTANT   ORIGIN    AND   LATER   DIFFUSION. 

In  the  United  States  our  chinch  bug,  Blissus  leucopterus,  has  a 
number  of  peculiar  characteristics,  which,  while  having  an  economic 
interest,  also  point  to  a  probable  previous  condition  differing  some- 
what from  the  present,  and  not  in  all  cases  tending  toward  its  present 
numerical  strength.  On  the  other  hand,  we  find  that  it  is  now  fol- 
lowing  some  probably  ancient  habits  which  do  not  appear  to  be  of 
any  special  benefit,  but  rather  the  reverse. 

In  the  first  place  over  its  area  of  greatest  destruction,  it  appears  to 
prefer  level  tracts  of  country  where  the  damp  conditions  consequent 
upon  frequent  rainfalls  remain  the  longest,  and  in  the  second  place, 
the  period  of  spring  oviposition  is  for  the  most  part  included  within 
that  during-  which  the  spring  rains  of  the  United  States  usually 
occur — that  is  to  say,  throughout  the  great  grain  belt,  east  of  the 
Rocky  Mountains,  April  and  May  are  not  normally  months  of  severe 
drought,  and  it  is  during  these  two  months  that  the  larger  portion 
of  the  eggs  are  deposited.  As  in  the  reverse  of  this,  however,  the 
period  of  fall  oviposition,  August  and  September,  is  far  more  likely 
to  be  favored  by  a  lack  of  precipitation.  These  conditions  do  not 
always  obtain,  and  it  is  because  of  the  fluctuations  that  the  insect 
is  able  to  reach  its  maximum  in  point  of  numbers. 

Another  factor  which  pla}^  quite  an  important  part  in  reducing  the 
number  of  adults  maturing  during  unfavorable  season.^  may  be  found 
m  the  almost  universally  gregarious  habits  of  the  young,  thereby  ren- 
dering the  ravages  of  fungous  diseases  the  more  universal  and  fatal. 
In  all  of  these  rjeculiar  characteristics  as  well  as  in  some  anatomical 
features,  it  would  seem  as  if  we  had  a  series  of  guide  posts,  so  to 
speak,  which  indicate  more  or  less  clearly  the  ancient  home  of  the 
sj:>ecies,  and  at  least  throw  some  light  on  its  origin  and  diffusion. 

UNIQUE    APPEARANCE    AND    GREGARIOUS    HABIT. 

Mr.  E.  A.  Schwarz  a  some  time  ago  called  attention  to  "  the  unique 
appearance  of  the  full-grown  chinch  bug,  with  its  white  wings  and 
chalky-white  pubescence/'  which,  he  declared,  "  forcibly  indicates 
that  the  insect  is  either  a  psammophilous  or  a  maritime  species,"  and 
expressed  the  opinion  that  its  geographical  distribution  fully  bears 
out  the  theory  that  it  belongs  to  the  latter  class.  The  same  author 
states  that  the  species  has  the  habit  of  clustering  about  the  roots  of 
lulu  of  grass  along  the  Atlantic  coast,  from  Florida  to  Atlantic  City. 
\.  J.,  and  Mr.  W.  IT.  Harrington  h  observed  it  to  have  the  same  habit 
along  the  seashore  at  Sydney.  Cape  Breton,  in  1884.     The  late  Dr. 

a  Insect   Life,   Vol.   VII.  p.  420. 
&  Can.  Ent,  Vol.  XXVI,  p.  218. 


PROBABLE    ORIGIN    AND    DIFFUSION.  75 

J.  0.  Neal,  while  at  Stillwater,  Okla.,  wrote  me  thai  he  had  observed 
the  species  to  have  the  same  habil  in  thai  Territory,  miles  from  any 
human  habitation.  Dr.  Asa  Fitch"  round  (hem  swarming  amidst 
extensive  prairies  in  Illinois,  in  L854,  while  more  recently  Mr.  C.  I;. 
Marlatt  has  witnessed  the  same  phenomenon  iii  Kansas.6  In  short, 
this  gregarious  habil  seems  to  ho  most  tenaciously  adhered  to  wher- 
ever these  insects  are  Pound  in  any  numbers.  When  migrating  from 
one  field  to  another,  after  crossing  a  roadway  or  plowed  held  they 
will  at  once  (lock  together  on  a  few  plants  along  the  margin  of  the. 
to  them,  new  field  instead  of  scattering  about,  two  or  three  to  a  plant. 
It  may  also  he  added  that  Mr.  Koebele  found  the  species  in  large 
numbers  along  the  seashore  not  far  from  San  Francisco,  ("ah.  in  the 
first,  second,  and  third  stages  of  development,  on  a  species  of  grass 
growing  along  the  coast. 

It  has  not.  so  far  as  is  known  to  the  writer,  been  observed  in  similar 
places  along  the  shores  of  the  Great  Lakes,  though  search  has  been 
made  for  it  there,  but  it  occurs  in  destructive  abundance  in  timothy 
meadows  inland  in  northern  and  northeastern  Ohio  25  to  75  miles  dis- 
tant, most  generally  clustering  about  the  roots  of  grass — which,  by  the 
way,  is  about  the  only  vegetation  attacked — as  the  species  is  described 
as  doing  along  the  seacoasts.  It  may  also  be  stated  that  it  seems  to 
hibernate  there  precisely  as  observed  by  Mr.  Marlatt  in  Kansas; 
Doctor  Xeal  in  Oklahoma ;  Mr.  Schwarz  in  Virgina  in  the  vicinity 
of  Fortress  Monroe,  and  as  the  earlier  observations  of  Doctor  Fitch 
in  Illinois  would  imply.  Thus  we  find  this  habit  of  clustering  upon 
the  plants  attacked  to  be  a  constant  one,  and  where  the  natural  grass 
vegetation  has  not  been  displaced  by  farm  crops,  thus  leaving  the 
ground  more  or  less  bare  during  winter,  the  chinch  bugs  continue  to 
hibernate  there.  With  these  two  characteristic  habits  generally  fol- 
lowed over  the  great  area  inhabited  by  the  species  in  North  America, 
we  may  add  a  third  possible  factor  in  the  problem  of  origin  and 
diffusion  of  the  species  which,  though  an  anatomical  dimorphism, 
may  be  discussed  as  likely  to  throAy  considerable  light  upon  the  prob- 
able ancient  habitat  of  the  insect. 

OCCURRENCE     OF     THE     LONG     AND     SHORT     WINGED      FORMS    AND     THETR 

DISTRIBUTION. 

The  occurrence  of  both  the  long  and  short  winged  forms,  inter- 
mixed along  our  seacoasts  and  in  the  northeastern  section  of  the 
country,  but  not  elsewhere,  shows  very  plainly  that  this  dimorphism 
is  not  due  to  the  temperature  of  any  particular  locality,  but  must 
be  regarded  as  having  been  brought   about  by  disuse  of  the  wings 

"Second  Report,  Insects  of  New  ¥ork,  ]).  283. 
&  Insect  Life.  Vol.  VII,  pp.  232-234. 


76  THE    CHINCB     BUG. 

for  a  considerable  period  of  time,  thus  indicating  a  seashore  habit 
on  the  one  side,  while  the  total  lack  of  the  short-winged  form  else- 
where indicated  otherwise. 

In  a  paper  presented  before  the  Entomological  Society  of  Wash- 
ington,a  "On  the  insects  found  on  Uniola  pamculata  in  southeastern 
Florida,"  by  Mr.  E.  A.  Schwarz,  the  author  stated  that  Blissus  leu- 
copterus  occurred  in  large  uumbers  on  the  upper  p?.rt  of  the  plant, 
the  imagos  and  larger  young  among  the  ear-  and  the  -mailer  indi- 
viduals between  the  upper  blades.  Mr.  Schwarz  attributes  this  habit 
to  the  tough  woody  nature  of  the  storm-beaten  plant  nearer  the 
ground,  thereby  driving  the  insect.--  to  the  more  tender  though  more 
exposed  portion  of  the  plant.  In  connection  with  this  statement  the 
writer  tells  us  that  the  insect  occurs  in  that  southern  latitude  only 
in  the  short-winged  form,  and  that  in  the  examination  of  thousands 
of  specimens  from  that  region  he  had  never  found  a  -ingle  lung- 
winged  specimen.  Under  date  of  May  4.  1896,  Mr.  W.  II.  Harring- 
ton wrote  of  this  species  as  follows:  "  In  September,  1890,  I  found 
it  at  Aulac  almost  on  the  border  between  New  Brunswick  and 
Nova  Scotia.  It  seemed  not  uncommon  and  occurred  under  -tone-. 
about  the  roots  of  grass,  in  a  pasture  adjoining  the  marsh  where  I 
found  Diabrotica  longicornis,  the  pasture  being  on  the  upland 
skirting  the  marsh.  Both  the  long-  and  short  winged  condition 
occurred,  as  in  Cape  Breton."6  Dr.  A.  S.  Packard  communicated 
to  Dr.  J.  A.  Lintner  the  following  extract  from  hi>  diary:  "  June  17. 
1871.  at  Salem.  Mass..  chinch  bugs  with  wing  covers  extending  over 
the  basal  third  of  the  abdomen,  seen  in  copula,  end  to  end.'  In  the 
serious  outbreak  of  this  insect  in  the  timothy  meadow-  of  northern 
New  York,  in  1882  and  1883,  about  :20  per  cent  of  the  bug-  were  of 
this  short-winged  form."'7 

Although  Dr.  Asa  Fitch.  a>  early  as  1855.  refers  to  this  form  along 
with  nine  others,  he  does  not  give  the  source  from  which  he  obtained 
specimens,  but  just  previous  to  this  he  says  (p.  287)  that  he  had  met 
with  but  three  specimens  from  his  own  State,  and  these  were  found 
on  willow  in  the  spring  of  1847/  Had  any  of  these  been  of  the  short- 
winired  form  he  would  have  been  very  likely  to  have  mentioned  the1 
fact.  Mr.  E.  P.  Van  Duzee  states  that  he  had  known  of  the  occur- 
rence of  the  species  in  western  New  Fork  a-  early  a-  L874,  and  had 
al-o  found  it  at  Ridgeway  and  Muskoka,  Ontario.  Ordinarily  the 
short-winged  form  predominates,  but  in  hot.  dry  summers  the  chinch 

iProc.  Km.  Soc.  Washington,  Vol.  l.  p.  104.     Read  Nov.  :;.  1887. 
&  Canadian  Entomologist,  Vol.  XIV,  p.  218. 

'  Lintner's  Second  Report,  State  Entomologist  of  New  York.  p.  164. 
d  Second  Report,  State  Entomologist  of  New  York.  j».  156. 
-      "lid  Report  mi  Noxious  Insects  of  Now  York.  p.  291. 
aadian  Entomologist,  Vol.  XVII,  pp.  209-210,  L886. 


PROBABLE    ORIGIN    AND    DIFFUSION.  77 

bugs  mostly  acquire  fully  developed  wings.  He  had  uever  found  the 
species  in  grain  fields  of  any  sort,  but  always  in  grass  land-,  generally 
in  timothy  or  clover,  but  sometimes  in  wdd  grasses.  ( )f  eleven  speci- 
mens collected  from  under  the  bark  of  an  old  log  by  Mr.  J.  Pettit,  of 
Grimsby,  Ontario,  in  L866,  and  sent  to  Mr.  B.  I).  \^  ;i  1  r- 1 »  for  determi 
nation,  all  were  of  the  short-winged  form.0  Ii  was  these  specimens 
that  doubtless  led  Doctor  Riley6  to  call  attention  to  the  fact  thai 
in  Europe  there  are  many  genera  <>f  half-winged  bugs  which  occur 
in  two  distinct  or  "dimorphous"  forms  with  no  intermediate  grades 
between  the  two.  viz,  a  short-winged  or  sometimes  a  completely 
wingless  type  and  a  long-winged  type.  Frequently  the  two  occur 
together  and  copulate  promiscuously,  while  sometimes  the  long- 
winged  type  occurs  in  particular  seasons,  especially  in  very  hot  sea- 
sons,  while  more  rarely  the4  short-winged  type  occurs  in  a  different  lo- 
cality from  the  long-winged  type,  and  usually  in  that  case  in  a  more 
northern  locality.  In  northeastern  Ohio  the  species  occurs  during 
some  years  in  great  abundance  and  wvy  largely  at  least  on  timothy. 
]{(')■{'  the  short-winged  form  is  very  largely  in  the  majority,  and  in 
the  spring  of  ls(.>7.  of  1,900  specimens  collected  indiscriminately, 
only  about  loo  were  of  the  long-winged  type. 

In  northern  Indiana,  where  the  insect  occurs  but  rarely,  this  short- 
winged  type  doe-  not  predominate;  but  aside  from  these  two  locali- 
ties, with  an  acquaintance  with  this  species  running  over  forty  years, 
chiefly  in  Indiana  and  Illinois,  the  writer  has  never  met  with  the 
short -winged  type  among  millions  of  adults.  If  this  short-winged 
type  occurs  elsewhere  to  the  westward,  except  along  the  Pacific 
coast,  where  both  forms  have  been  collected  by  Koebele  and  others, 
it  has  not  been  found  by  entomologists,  even  to  the  northward  as 
far  a-  Minnesota,  Winnipeg,  and  Manitoba,  while  to  the  eastward 
of  this  Mr.  Van  Duzee  collected  the  brachypterous  form  on  Muskoka 
River,  Ontario,  near  the  lake  of  that  name/  On  comparing  speci- 
men- from  New  York  with  a  large  series  from  Kansas,  the  former 
were  found  to  be  quite  uniformly  more  robust,  with  longer  hairs 
on  the  pronotuni.'' 

It  would  seem  that  here  we  have  evidence  of  two  distinct  tides  of 
migration,  the  one  -weeping  north  and  eastward,  while  the  other  has 
mainly  been  to  the  north  and  westward.,  meeting  the  former  in  north- 
eastern Ohio  and  northern  Indiana,  and  possibly  somewhere  farther 
to  the  north  in  British  America.  The  two.  besides  differing  in  the 
length  of  the  wing-,  are  sufficiently  unlike  in  appearance  to  attract 
the  attention  of  students  of  Hemiptera. 

"  Practical  Entomologist,  Vol.  EI,  p.  21. 

b  Second  Report  on  tin-  Insc-is  of  Missouri,  p.  22,  1870, 

'('.•in.  Km..  Vol.  XXI.  p.  ::.  1889. 

(i  Lor.  cit,  Vol,  XVII  I.  p.  209, 


78  THE    CHINCH    BUG. 

RELATION    OF    THE    INLAND    AND    BEACOAST    SHORT-WINGED    FORMS. 

It  is  possible  thai  the  short-winged  form  of  chinch  bug  found  in 
Ohio  is  precisely  the  same  form  as  that  found  along  the  seacoasts, 

hut  it  seems  to  the  writer  that  the  inland  form  originating  from  this 
maritime  short-winged  element,  instead  of  acquiring  wings  of  normal 
length  as  it  drifted  away  from  the  coast,  has  really  moved  in  the 
other  direction,  and  the  wings  have  become  still  further  aborted. 

It  will  be  observed  by  the  illustrations  given  of  both  the  inland  and 
maritime  short-winged  forms  (see  figs.  3  and  4)  that  in  some  of  the 
former  the  wings  have  become  so  aborted  as  to  become  almost  invisi- 
ble, while  in  the  latter,  though  the  wings  are  very  much  shortened, 
they  are  nevertheless  very  clearly  to  be  observed.  It  would  seem. 
then,  that  we  might  reasonably  presume  that  the  species  was  orig- 
inally Long-winged,  but,  living  along  the  seashore,  the  winged  indi- 
viduals have  either  flown  each  year  inland  or  else  been  blown  into  the 
sea  to  such  an  extent  that  a  short-winged  form  has  thus  been  evolved 
which  was  unable  to  migrate  and  not  easily  blown  into  the  sea.  In 
pushing  inland  while  the  country  was  still  inhabited  by  the  aborig- 
inees  another  source  of  destruction  would  confront  these  insects  in 
the  annual  recurrence  of  fires  whereby  vast  areas  of  country  were 
burned  over  in  autumn,  winter,  or  early  spring,  and  these  must  have 
destroyed  very  many  of  the  hibernating  insects,  while  such  indi- 
viduals as  migrated  to  sections  not  so  burned  over  would  escape 
destruction. 

PROBABLE    COURSE    OF    DIFFUSION. 

Let  us  suppose  that  the  species  originally  worked  it>  way  north- 
ward from  South  America,  or  even  Panama,  along  the  lowlands  be- 
tween the  more  mountainous  interior  and  the  Gulf  of  Mexico  until 
it  reached  Texas  with  its  vast  areas  of  level  country  extending  not 
only  aero—  the  State  itself,  but  northward  into  British  America,  and. 
generally  -peaking,  with  the  exception  of  the  Ozark  Mountains  in 
Missouri  and  Arkansas,  eastward  to  the  Appalachian  system  extend- 
ing from  Cape  Gaspe,  Quebec,  Canada,  to  northern  Alabama.  This 
area  is  more  or  le>s  covered  with  a  grass  flora  that  affords  ample  food 
for  these  insects,  and  it  would  seem  that  then1  was  here  offered  every 
incentive  t<»  migration  broadly  to  the  northward  and  eastward,  and 
at  the  same  time  there  would  be  the  Gulf  coast  along  which  those 
individuals  which  either  could  not  or  did  not  migrate  inland  could 
make  their  way  as  had  their  progenitors  along  the  coast   in  Mexico. 

(  See    fig.    1  7.  ) 

Now.  it  would  appear  a-  though  the  short-winged  individual-,  if 
there  were  any  such,  would  remain  along  the  coast,  while  the  long- 
winged  individuals  would,  at  leasl  more  or  less  of  them,  migrate  in- 
land, and  at  leasl  some  of  these,  but   far  more  of  those  unable  to  flv. 


PROBABLE    ORIGIN    AM)    DIFFUSION. 


F"'-  ]~      Map  showing  probable  course  of  diffusion   of  cbinch   bug  over  North   America. 

i  Ami  bor's  illust  ral  Ion.  I 


80  THE   CHINCH   BUG. 

would  be  annually  destroyed  by  the  prairie  fires,  thus  eliminating 
whatever  tendency  there  mighl  be  to  perpetuate  the  brachypterous 
forms,  and  develop  a  fully  winged  more  or  less  nomadic  race  which. 
as  it  slowly  advanced  inland,  lost  all  vestige  of  it-  brachypterous 
ancestry,  i  f  such  had  existed.0 

( )n  the  other  band,  we  might  expect  the  shore-inhabiting  in- 
dividuals to  continue  in  their  progress  along  the  coast,  the  winged  in- 
dividual- continually  migrating  inland,  leaving  a  mixture  of  the  two 
forms  to  push  forward  to  the  east  coast  of  Florida — where  a-  late  as 
L906  it  attacked  grass  on  lawn-  about  Palm  Beach— and  northward 
along  the  Atlantic  to  Cape  Breton.  A-  soon  a-  this  migration  had 
passed  the  southern  terminus  of  the  Allegheny  Mountains  the  inland 
spread  would,  very  largely  at  least,  he  restricted  to  the  area  lying  be- 
tween the  eastern  slope  of  these  mountain-  ami  the  coast,  thus  leav- 
ing the  whole  area  to  the  west  to  be  occupied  by  the  northward  tide 
of  migration  instead  of  that  from  the  east.  East  of  the  Mississippi 
River  and  south  of  the  Ohio  River  the  country  i-  more  heavily  tim- 
bered and  the  prairies  are  lacking,  so  that  forest  fires  would  here 
take  the  place  of  prairie  fires;  but  in  the  Southern  State-  the  wood- 
are  composed  more  largely  of  pine,  and  Doctor  Lugger,  in  Minnesota, 
found  that  the  chinch  bug  did  not  invade  the  region  on  which  only 
pine  and  other  Coniferae  grew,  hut  that  the  more  southern  counties 
of  his  State,  which  are  more  or  less  wooded  with  deciduous  tree-,  were 
invaded.  lie  also  called  attention  to  the  fact  that  before  the  country 
wa-  settled  by  the  Avhites  these  timbered  lands  were  burned  over  fre- 
quently, probably  annually,  but  now  the  wooded  areas  are  confined  to 
small  tract-  interspersed  among  the  farm-,  and  as  these  are  not  an- 
nually burned  over  they  afford  suitable  -belter-  for  the  chinch  bug 
during  winter,  and  the  grain  fields  of  the  farmer  afford  ample  food 
during  the  summer,  while  on  the  prairie-  which  are  burned  over  such 
is  not  the  case.6 

Along  the  eastern  coast  the  chinch  bug  has  never  been  especially 
destructive  to  the  wheat  crop  north  of  North  Carolina,  where,  accord- 
ing t<>  Doctor  Fitch.''  the  earliest  depredation-  occurred  in  1783,  while 
Webster d  states  that  it  threatened  total  destruction  to  the  grain  in 
17^r»:  but  since  that  time  the  ravages  have  not  been  nearly  a-  severe  as 
farther  west   in  the  Mississippi   River  Valley.     In   1899,  1000.  1901, 


a  Prof.  II.  A.  Morgan,  then  entomologist  of  the  State  Experiment  Station  of 
Louisiana,  writing  under  date  of  May  30,  1898,  states  that  he  has  never  found 
the  brachypterous  form  of  chinch  bug  in  that  State,  and  the  writer  did  not 
observe  a  single  individual  el'  these  among  the  many  macropterous  specimens 
taken  by  himself  in  that  State. 

&Firs1  Annual  Reporl  of  the  Entomologist  of  the  state  Experiment  Station  of 
the   University  of  Minnesota,    1895,   p.   26. 

'•  Second  Report  on  Noxious.  Beneficial,  and  other  Insects  of  New  York-,  p.  278, 

i  Webster  on  Pestilence.  Vol.  I.  \k  279, 


PROBABLE    ORIGIN     \M>    DIFFUSION.  Si 

and  L902  this  maritime  form  destroyed  the  timothy  in  the  vicinity  of 
Reidsville,  N.  C.  This  is  on  the  southern  border  of  timothy  culture 
along  tin1  Atlantic  coast,  and  some  years  ago  an  attempt  was  made  to 
grow  timothy  In  thai  seel  ion.  The  grass  did  ?ery  well  until  the  above 
mentioned  attack  occurred,  and  by  L905  there  was  but  little  remain- 
ing." Strangely,  too,  uowhere  along  the  Atlantic  coast  do  we  find  the 
short-winged  individuals  far  inland  until  we  reach  New  York  and  the 
New  England  States,  and  what  is  equally  perplexing  they  do  not  there 
attack  grain,  but  grass,  whereas  to  the  southward,  except  near  the  sea- 
coast,  it  is  the  grain  fields  that  are  devastated  by  the  long-winged 
form.  In  other  word-,  throughout  New  England,  New  York,  north- 
eastern Ohio,  northern  Indiana,  and  the  Dominion  of  ( 'ana da  we  have 
both  the  lone-  and  short  winged  individuals  occurring  together,  but 

.—  S3  -  too 

depredating  almost  or  quite  exclusively  upon  timothy  (Phleum  pra- 
tensi  ). 

In  Bulletin  IT.  old  series,  Division  of  Entomology,  U.  S.  Depart- 
ment of  Agriculture,  Dr.  L.  ().  Howard,  the  author,  stated  thai  in 
L88G  a  timothy  meadow  located  near  Wakeman,  Huron  County,  Ohio, 
was  considerably  injured  by  chinch  bugs.  Since  that  time  the  species 
ha-  never  been  reported  from  that  section  of  the  State,  and  the  writer 
ha-  found  that  depredations  of  that  particular  character  are  only 
committed  by  the  more  or  less  brachypterous  race.  This  ha-  been 
supposed  to  be  largely  confined  to  the  northeastern  portion  of  the 
State,  though  there  seems  to  he  no  good  reason  why  it  should  not 
appear  in  northwestern  Ohio  also.  Owing  to  these  facts  tin-  -ingle 
occurrence  in  meadows,  recorded  by  Doctor  Howard,  formerly  puz- 
zled the  writer  greatly. 

During  the  fall  of  1898  there  came  reports  of  very  serious  destruc- 
tion of  meadow-  in  Huron  and  Lorain  counties,  which  lie  contiguous 
to  each  other,  the  cau-e  being  attributed  to  the  dry,  hot  weather.  But 
an  examination  of  the  meteorological  records  for  that  section  revealed 
the  fact  that  there  had  been  no  weather  condition  sufficiently  severe 
to  affect  timothy  meadows  in  that  way.  A  survey  of  the  affected 
meadow-  during  early  spring  of  180;)  revealed  the  presence  of  great 
number-  of  brachypterous  chinch  bug-  hibernating  in  these  meadow-, 
and  the  problem  was  solved.  The  species  had  doubtless  been  doing 
more  or  less  injury  since  1886,  entirely  unknown  to  the  farmer  or  any- 
one   el-e.    thus    -bowing    the    extent     to    which     it-    secluded     life     in 

meadow-  protect-  it  from  observation.  This  section  of  the  State 
since  1886  has  been  more  largely  devoted  to  dairying,  and  the 
meadows  are  not  a-  rapidly  rotated  with  other  crop-  as  when  the 
cereal-  were  grown  more  extensively. 

Extract    Prom   correspondence  of   Prof.    Franklin    Sherman,  jr.,   State   <'iitu- 
mologist. 

26608— No.  69—07  w <; 


82  THE    CHINCH    BUG. 

In  Ohio,  which  appears  to  be  the  frontier  of  destructive  abundance, 
the  line  separating  the  habitat  of  the  combined  form-  and  that  of  the 
macropterous  form,  exclusively,  indistinctly  marks  the  line  of  separa- 
tion between  the  most  serious  depredations  and  almost  total  immunity 
of  attack  on  timothy  meadow-  by  chinch  bugs.  To  the  west  and 
south  of  this  a  short-winged  adult  chinch  bug  is  rarely  seen,  timothy 
meadows  are  seldom  attacked,  and  then  only  where  held-  of  small 
grain  or  corn  are  not  in  easy  reach:  a-,  lor  illustration,  where  the  in- 
sect happens  to  breed  in  a  wheat  field  surrounded  by  timothy,  and. 
when  the  grain  is  harvested,  there  is  no  other  recourse  left  it  hut  to 
attack  the  grass.  In  the  opposite  direction  from  our  line,  however. 
the  conditions  are  quite  the  reverse.  Here,  while  fields  of  wheat  are 
occasionally  badly  injured,  thousands  of  acres  of  timothy  meadow 
have  been  entirely  killed  out  from  it-  attack. 

The  area  of  destructive  infestation  of  timothy  meadow-  seems  to 
extend  on  the  east  in  Ohio  from  Lake  Erie  to  the  Ohio  River  at  the 
northernmost  point  of  West  Virginia,  and  on  the  west,  in  the  vicinity 
of  Sandusky,  it  extends  only  25  or  30  miles  from  the  lake  shore.  In 
limited  numbers  the  area  of  distribution  extend-  westward,  probably 
narrowing  gradually,  around  the  lower  end  of  Lake  Michigan  into 
northern  Illinois,  where  it  seems  to  be  on  the  increase,  though  >till 
far  from  common.  As  will  be  shown  further  on.  this  form  is  not 
likely  to  become  destructive  where  timothy  is  grown  in  rotation  with 
other  farm  crops. 

So  far  as  it  is  possible  to  determine,  there  are  a  considerable  number 
of  winged  adults  produced  in  this  area  every  year — perhaps  from  30 
to  50  per  cent  some  seasons — and  these  breed  in  the  grain  held-:  but 
at  wheat  harvest,  instead  of  migrating  to  the  corn,  as  i>  done  else- 
where,  they  go  by  preference  to  the  timothy  meadow-.  In  western 
New  York,  where  both  the  long  and  short  winged  forms  occur.  Mr. 
Van  Duzee  wrote  that  he  had  neA'er  found  an  individual  of  either 
form  in  grain  fields,  but  that  they  both  literally  -warm  in  timothy 
during  some  year-.  Doctor  Lintner  told  the  writer  that  in  the  serious 
outbreak  of  this  pest  in  the  meadows  of  Xew  York  in  1882  and,  L883 
about  20  per  cent  were  of  the  short-winged  form.  Doctor  Perkins  has 
recorded  an  attack'  of  the  chinch  bug  in  a  timothy  meadow  in  northern 
Vermont.  Whether  or  not  the  short-winged  form  was  the  depredator 
in  this  last-named  locality  the  writer  i>  unable  to  say,  but.  generally 
-peaking,  the  short-winged  form  is  unknown  at  any  considerable 
distance  from  the  coast,  except  in  Maine,  New  York,  Ohio.  Ontario, 
and  northern  Indiana,  and  but  rarely  doe-  it  occur  in  either  form  in 
the  two  latter  localities. 

Just  why  this  short-winged  form  should  occur  in  such  abundance  in 
the  three  States  named  i-  a  matter  that  the  writer  is  at  present  unable 
fully  to  explain :  but  it  doe-  seem  that  this  difference  in  food  habits  a- 


EABITS    OF    THE    EUROPEAN    BLISSUS    I»mi;i.i. 


83 


between  the  two  forms  and  the  limited  distribution  of  the  short- 
winged  form  inland  might  open  the  way  to  a  solution  of  the  mystery. 
The  writer  believes  that  the  insect  is  primarily  a  tropica]  macrop- 
terous  species,  and  that  it  has  followed  the  coast  from  South  A.merica 

along  the  Gulf  and  Atlantic  northward  to  ('ape  Breton,  and  along 
the  Pacific  coast  to  San  Francisco  and  possibly  beyond;  also  thai  it 
spread  from  northern  Mexico  and  Texas  northward  as  far  as  Winni- 
peg, subsisting  upon  the  native  grasses,  and  in  the  meantime  spread- 
ing also  to  thi'  eastward  to  northern  Indiana  and  Ohio. 
[  On  the  other  hand,  from  the  Atlantic  coast  there  has  originated  a 
tide  of  diffusion  the  trend  of  which  has  been  westward,  the  bugs 
here  partaking  more  of  the  nature  of  their  seashore  ancestors,  more  or 
less  of  them  being  of  the  short-winged  form,  which  their  Less  nomadic 
habit  has  served  to  further  emphasize.  This  tide  of  diffusion  has  en- 
countered what  the  western  tide  did  not,  at  least  until  much  later, 
namely,  the  timothy  meadows  of  the  Caucasian  agriculturist,  ami. 
adapting  it-elf  to  this  food 
plant,  ha-  held  closely  to  it. 
thus  avoiding  the  necessity 
of  seasonal  migration.  In 
northeastern  ( )hio  and  pos- 
sibly in  northern  Indiana 
and  northern  Illinois  the 
western  tide  of  diffusion 
has  met  the  eastbound  tide 
and  i-  perhaps  amalgamat- 
ing with  it.  (See  map. 
fig.  17.  illustrating  sup- 
posed direction  of  diffusion 
of  chinch  bug. ) 

Although  not  at  all  conclusive  evidence,  it  might  be  added  that  the 
-ingle  specimen  taken  at  Winnipeg  by  Doctor  Fletcher  was  of  the 
macropterous  form,  while  the  single  example  taken  by  Mr.  Van  I  >uzee 
at  Muskoka,  Canada,  was  of  the  brachypterous  form:  and  this,  with 
the  fact  that  the  specimens  from  the  island  of  Grenada  were  of  the 
former  and  the  Florida  coast  specimens  of  the  latter  exclusively, 
-how-  that  latitude  and  climate  have  no  effect. 

HABITS   OF    Mil.    i:i   ROPEAN    SPECIES,    BLISSUS    DOR-E    FERR. 

Prompted  apparently  by  a  review  of  one  of  the  writer's  papers 
read  before  the  eighth  annual  meeting  of  the  Association  of  Economic 
Entomologists  nt  Buffalo  in  L896,  Prof.  Karl  Sajo,  formerly  of  the 
Kg.  Tug.  Staatliche  Entomologische  Versuchsstation,  at  Budapest, 
published  a  short  paper  on  "Unser  Blissus  doria?" Q  which  is  so  full  of 


Fig.  18.— Bliestis  dorice:  ",  first  nymph;  c,  second;  b,  tl 
-/.  fourth.    (From  illustrations  prepared  in  the  Bureau 

of  Kntomology.) 


olllustr.  Wachenschrift  Cur  Entoniologie,  Vol.  II.  pp.  449-451,  -Inly  18,  1891 


84 


THE    CHINCH    BUG. 


interest  that  the  writer  has  reproduced  it  here,  together  with  figures 

of  the  larval,  pupal,  and  adult  stages  of  the  insect  <  figs.  Is  and  19). 
Professor  Sajo  writes  a-  follow-: 

in  the  article  od  the  eighth  annual  meeting  of  the  Association  of  Economic 
Entomologists  (No.  26,  pp.  401-403,  Illustr.  Wochensehrift  fur  Entomologie)  the 
very  instructive  observations  of  .Mr.  Webster  on  the  "chinch  bug"  (Blissus 
l<  ucopterus)  in  the  State  of  Ohio  were  discussed. 

In  view  of  this  communication  I  will  Lrive  more  in  detail  that  which  I  have 
observed  concerning  our  European  species  of  this  genus,  namely  Blissus  doria 
Ferr. 

Like  the  North  American  larger  species,  the  smaller  European  one  appears  in 
two  forms,  namely,  the  wingless  and  the  winged.  The  firsl  describer  of  this 
species,  Ferrari,  in  Genoa,  recognized  only  the  wingless  form,  which  with  its 
aborted  wings  looks  very  much  like  Hemipteron-nymphs,  and  probably  by  all 
entomologists  who  previously  saw  it  was  not  considered  as  a  sexually  developed 

adult,  hut  only  the  immature  form 
•  f  -'"me  already  known  species.  I 
discovered  the  winged  form  seven- 
teen year-  ago  i  1880)  in  the  steppes 
sand  desert,  called  "  Nyires "  of 
the  Kis-Szent-Miklos,  and  de- 
scribed the  same." 

I  at  that  time  made  known  the 
characters  of  the  immature  form-. 
which  can  not  he  confused  with 
the  individuals  which  have  readied 
complete  sexual  development,  in 
that  the  immature  individuals  are 
vermilion  red  while  adult  indi- 
viduals are  dark  brown.  It  is 
interesting  that  the  relationship 
between  the  winged  (macropte- 
rous)  and  the  wingless  (brachypterous)  individuals  of  the  American  and  Euro- 
pean species  is  very  different.  For  while  in  America  those  individuals  which 
reach  maturity  are  almost  always  winged,  with  us  in  Europe  they  are  in  gen- 
eral only  short-winged,  and  individuals  capable  of  flight  are  not  observed: 
and  the  fully  developed  macropterous  individuals  were  not  thus  far.  according 
to  my  knowledge,  found  in  any  other  place  than  in  the  central  Hungarian  sand 
dunes  already  named,  and  here  they  occurred  only  on  a  single  little  portion  which 
only  measured  a  few  paces  in  diameter.  It  was  a  "  Dunenhugel"  (sandy  hill) 
covered  with  high,  scattered  poplars,  whose  fallen,  dried  foliage  Sparsely  cov- 
ered I  he  ground. 

Here  lived  the  colonies  i^\'  BliSSUS  doria  on  the  bases  of  the  bushy,  -rowing 
grass,  almost  under  the  surface  of  the  ground,  and  well  concealed.  The  habits 
of  the  European  species  are  also  in  the  main  similar  to  those  of  its  American 
relative,  since  the  latter  also  lives  only  on  grasses,  and  during  its  development 
also  lives  very  close  to  the  surface  of  the  ground. 

It  is  extremely  remarkable  that,  even  though  /»'.  doriw  is  very  widely  distrib- 


■'::■■:-,■■ 


Fig.  19.— Blissus  doria::  Wingless  form  at  left;  winged 
form  at  right.  (From  illustration  prepared  in  the 
Bureau  of  Entomology.) 


K.  Sajo:  "  Die  bisher  unbekannte  makroptere  Form  von  Blissus  d<>ri<i  Ferr. 
Entomolog.  Nachrichten,  L880,  p.  2 


(' 

sai 

d  drl 

fts), 

mi  also 

of 

the 

hill 

v\  liicl 

stands 

roll 

Qg 

hills) 

.  the 

Blis 

sua 

Ishin 

1  -  in 

der  the 

an 

I   o 

ily    II 

ten  w 

hi  ii  the 

i   full    t 

irce. 

\\  'in 

ii   there 

or  ! 

mg 

w  lng< 

Ml     ill.l 

[viduals 

Qge< 

I  ex 

amp] 

is,  as 

soon  .-is 

iear 

id 

ii  on 

Ler  ii 

a1    thej 

BABITS    OF     INK    EUROPEAN     BLISSUS    hoi;  i.e.  S,~) 

n t fi i  here,  and  is  met  with  not  only  on  the  '*  Flugsandi 
in  the  hilly  regions   (e.  g.,  on  the  southern  exposure 
between   Duka  and  Szod,   in  the  midsl   of  bluffs  or 
specimens  were  to  be  found  only  on  the  very  sm.-iil  "  i 

poplars.      Bui    hero   nlso    i  hoy    were    found    bu1    rarely. 

transformation  from  the  pupa  to  adull  stage  was  ii 
were  no  aiore  pupae  to  be  round,  then  nlso  the  search  f< 
w as  in  vain. 

This  appearance  I  explain  in  this  way:  Thai  the  wi 
they  were  able  to  By,  quickly  flew  away  and  disap] 
mighl  serve  as  progenitors  for  now  colonies. 

Bui  the  place  of  discovery  has  since  been  transformed  into  an  immense  vine 
yard  by  the  Government,  whereby  grass,  poplars,  and  nlso  /;.  doria  had  to  disap- 
pear from  thence.  For  four  years  l  have,  though  seeking  with  the  greatesl 
diligence,  been  unable  to  gel  track  of  the  winged  specimens  anywhere  in  this 
region,  even  though  I  know  of  a  number  of  colonics  of  this  species  upon  my  own 
premises.  While  formerly  I  captured  a  few  specimens  each  year  and  gave  them 
partly  to  museums  and  partly  to  entomologists,  I  scarcely  hope  to  attain  such 
interesting  finds  in  the  future.  >i 

The  difference  just  mentioned  between  those  individuals  capable  of  flighl  and 
those  not  capable  of  flighl  in  our  species  and  also  in  the  transatlantic  species 
can  hardly  be  accidental,  but  may  be  soughl  for  in  the  influences  of  environment. 

Next  there  crowds  to  the  front  the  fact  that  in  North  America  /».  leucopU  rus  is 
continually  subjected  to  the  attack  of  its  deadly  fungus  parasite  toa  high  degree, 
and  its  colonies  die  out  as  soon  as  rainy,  moist  atmosphere  prevails.  Conse- 
quently, the  Blissus  species  living  there  must  always  hunt  new  habitats  and  be 
wandering  continually  to  far  distant  localities.  For  this  wings  are  of  course 
necessary,  and  only  by  means  of  these  is  the  species  enabled  to  sustain  itself  at 
such  a  high  grade  of  importance  that  it  can.  now  here,  now  there,  become  a  veri- 
table plague  to  agriculture. 

With  our  European  species  it  seems,  on  the  contrary,  in  regard  to  many 
points  to  he  otherwise;  for.  while  her  habits  in  the  main  are  similar  to  those  of 
her  sister  across  the  sea.  yet  there  are  found  many  important  differences  in 
their  environment. 

Blissus  doria  never  congregates  in  such  close  masses  as  we  read  of  in  the 
American  reports.  It  forms  only  insect  islands,  and  even  individual  families 
seem  to  scatter  out  to  some  distance.  In  the  steppes,  moreover,  the  growth  of 
grass  is  not  matted,  hut  stands  in  isolated  hunches  on  the  partially  hare  ground 
the  hunches  being  not  infrequently  separated  by  several  paces. 

our  species  will  not  go  into  cultivated  fields.  I  have  never  found  even  a 
single  specimen  among  forage  plants  that  have  been  sown,  and  already  this 
condition  is  one  of  the  reasons  why  the  European  species  does  no1  cluster 
together  in  such  uninterrupted   musses. 

If.  then,  this  is  true  the  attacks  of  entomogenous  fungi  will  hardly  he  able  to 
create  such  havoc  in  Ii.  dorin  as  it  does  among  />.  leucopterus  in  America. 

I  have  nlso  during  eighteen  years  never  observed  a  wholesale  dying  off  in  the 
localities  of  occurrence  known  to  me.  The  fungus  -s'.  globuliferum  has  perhaps 
never  attacked  it.  and  even  though  the  European  form  were  susceptible  to 
similar  pestilences,  yet  it  is  always  hardly  to  he  doubted  that  the  fungus  in  the 
European  homes  ,,f  /;.  doriw  would  not  find  favorable  circumstances  in  that 
here  during  the  period  of  development  of  this  species  in  normal  years  great 
drought  prevails.  Rains  lasting  for  a  number  of  days,  with  continued  moisl 
ami   warm   atmosphere,   belong,   with    us.   among   the   rarities,   especially   during 


86  THE    CHINCH    BUG. 

the  summer,  and  it  is  the  young  stages  that  are  especially  sensitive  to  the  fun- 
gus attack,  as  has  proven  to  be  the  case  in  America. 

Among  insects  there  may  possibly  be  found  Blissus  enemies,  even  though  the 
emely  penetrating  odor  of  this  bug,  which  is  identical  with  that  of  the  one 
living  in  beds  in  bouses,  may  serve  as  a  protection. 

Taking  all  of  this  together,  we  observe  that  our  European  species  is  in  less 
danger  than  the  American,  and  that  ii  is  not  subjected  to  catastrophes  of  total 
destruction,  so  far  as  has  yet  been  i  bs  rvable  in  the  stationary  localities  of  occur- 
rence in  the  open  field,  for  1  have  never  yet  observed  a  sudden  disappearance 
from  the  localities  known  to  me.  It  is  not  necessary,  therefore,  for  it  to  be 
continually  hunting  up  new  fields  in  which  to  thrive,  and  there  was  no  appar- 
ent reason  which  in  the  struggle  cor  existence  would  have  given  preponderance 
to  the  long-winged  form:  and  so  in  time,  in  the  generation  of  our  species, 
which  originally,  perhaps,  was  full  winged,  the  winged  form  became  less  and 
less  numerous,  until  to-day  we  see  almost  entirely  brachypterous  individuals 
in  the  adult  stage,  exactly  the  same  as  in  the  bedbug,  Acanthia  lectularia,  with 
this  difference,  that  among  the  swarming  masses  of  the  latter  nowadays  oot 
a  single  example  with  fully  developed  wings  can  be  found,  fortunately  for  us. 

It  is  evident  that  the  long-winged  tendency  in  />'.  doria  is  disappearing,  and 
the  time  may  come  when  one  will  he  unable  to  find  any  long-winged  specimens. 
The  designated  dangers,  on  the  contrary,  against  which  the  chinch  bug  must 
fight  in  North  America  require  very  strong  migratory  powers,  and.  conse- 
quently, well-developed  wings,  through  which  this  especially  significant  differ- 
ence between  B.  doria  and  B.  leucopterus  has  been  brought  about. 

As  to  the  question  whether  or  not  our  species  shall  be  considered  injurious.  I 
can  answer  that  it  in  no  wise  belongs  to  the  entirely  indifferent  insects,  but.  on 
the  contrary,  contributes  to  the  complete  drying  up  of  the  rather  sparse  grj  ss  3 
of  our  steppe  meadows  during  the  summer.  But  since  it  has  not  thus  far 
boused  in  the  cultivated  fields,  it  can  not  he  placed  upon  the  black  list  of  seri- 
ous depredators.  Whether,  moreover,  in  the  future,  when  in  consequence  of 
the  continued  destruction  of  its  herding  meadows,  its  original  food  plants  dis- 
appear more  and  more.  11.  doriw  may  become,  like  so  many  other  insect  species, 
a  depredator  through  necessity  can  only  be  conjectured.  We  have  in  this  re- 
gard already  recorded  entirely  too  many  remarkable  transformations  in  the 
menu  of  other  species  to  disregard  entirely  the  possibility  of  a  similar  transfor- 
mation in  the  life  habits  of  our  B.  doriw. 

I  wish  also  at  this  time  to  state,  for  the  benefit  of  our  many  readers  who  may 
not  he  familiar  with  it.  that  in  the  dimorphic  bugs,  especially  those  in  which 
the  macropterous  and  brachypterous  forms  are  found  simultaneonsly,  the 
former  possess  a  much  stronger  and  broader  thorax  than  the  latter.  As  a 
result  of  this  difference  in  their  physical  structure,  one  is.  when  comparing 
them  for  the  first  time,  easily  inclined  to  designate  them  as  two  distinct  sp< 

In  addition  to  this,  there  is  in  Blissus  the  strikingly  beautiful  coloration  of 
the  long-winged  specimens,  whose  clavus  and  corium  art'  1  i lt  1  i t  ocher-yellow,  and 
the  unusually  large  membrane,  which  is  about  twice  as  large  as  corium  and 
clavus  together  and  of  an  entirely  milk-white  color,  making  the  long-winged 
individuals  very  prepossessing.  The  individuals  with  rudimentary  wings,  on 
the  contrary,  are  of  an  obscure  chocolate-brown.  The  larvae  are.  as  has  already 
been  stated,  of  a  bright  vermilion-red  color,  marked  with  black.*" 

\\\\\\  the  foregoing,  relative  to  the  habits  of  an  allied  spfecies  <>1* 
Blissus,  it  seems  to  the  writer  that  we  can  the  better  understand  how. 


'Translated  from  the  German  by  Mr.  < '.   W.  Mally. 


• 


PROBABLE    ORIGIN    AND    DIFFUSION,  S, 

under  one  set  of  conditions,  all  traces  of  a  short-winged  form  might 
entirely  disappear,  while  with  another  se<  of  conditions  this  tendency 
might  not  only  be  perpetuated,  but  greatly  emphasized.  The  two 
species,  B.  leucopterus  and  />.  dorice,  are  fully  illustrated  in  all  stages 
of  development,  as  well  as  U>th  macropterous  and  brachypterous 
Forms.  (See  figs,  on  pp.  21,  22,  23,  s-"».  84.)  For  specimens  of  the 
latter  species,  />'.  dorice,  we  arc  indebted  to  Professor  Sajo. 

PREVIOI  8   IDEAS  <»N    THE  DIFFUSION   OF  THE  CHINCH    BUG. 

Formerly  it  was  supposed  that  the  chinch  bug  was  a  Dative  of  the 

Atlantic  coast  State.-,  and  that  it  made  its  way  westward  with  the 
advance  of  civilization  and  the  consequent  progress  of  wheat  gro^  ing. 
This  theory  was  based  upon  the  fact  that  the  original  description  was 
drawn  up  from  a  specimen  from  the  eastern  shore  of  Virginia,  col- 
lected by  Mr.  Say  himself,0  and.  as  before  stated,  the  earliest  destruc- 
tion on  record  caused  by  this  insect  occurred  in  North  Carolina,  and 
it  also  committed  great  depredations  in  Virginia  in  L839.  Up  to  this 
time  it  had  been  supposed  that  it  was  a  southern  specie-,  confined  to 
the  country  south  of  latitude  40°  north.  But  about  this  time  chinch 
bugs  appeared  in  Illinois,  at  Nauvoo,  simultaneously  with  the  settle- 
ment of  the  Mormons  at  that  place,  and  as  many  supposed  that  this 
sect  brought  the  bugs  to  the  country  with  them,  they  were  locally 
termed  "  Mormon  lice.*' 

In  his  second  report,  page  284,  Doctor  Fitch  states  that  Mr.  Wil- 
liam Patten,  of  Sandwich.  Dekalb  County,  111.,  informed  him  that  the 
chinch  bug  first  appeared  in  that  locality  in  1850.  Mr.  Patten,  the 
father  of  Prof.  Simon  Patten,  of  the  University  of  Pennsylvania, 
and  the  writer's  father,  settled  in  the  immediate  vicinity  of  Sandwich. 
111.,  in  1852.  This  was  ten  year-  after  the  Pottawattamie  chief,  Shab- 
bona,  and  his  tribe  had  migrated  to  Kansas  or  Nebraska,  the  writer 
does  not  remember  which,  but  he  does  recall  that  it  was  about  this  time 
that  the  prairie  fires  ceased  to  occur  over  any  wide  areas,  as  the  prairies 
were  no  longer  fired  annually  by  the  Indians.  The  wrhole  country  was 
fast  being  occupied,  and  he  well  remembers  that  the  settlers  would 
decide  upon  a  certain  date-  on  which  they  would  set  fire  to  the  wild 

gra in  late  autumn — SO  that  all  could  he  prepared.     It  may  also  he 

stated  that  there  were  very  few  timothy  meadow-  at  that  time.  a-  the 
wild  grass  afforded  an  abundance  of  hay.  and  not  until  years  after 
did  cultivated  grasses  come  into  general  use.  The  writer  also  knows 
from  persona]  experience  and  observation  that  with  the  decrease  in 
prairie  fire-  there  came  an  increasing  abundance  of  chinch  bugs, 
which  attacked  the  wheat  fields  of  the  farmer.  Up  to  about  L862 
these  field-  were  largely  of  spring  wheat,  hut  about  that  time  there 

»The  complete  writings  of  Thomas  Say,  edited  by  Le  Conte,  Vol.  I.  p. 


88  THE    CHINCH    BUG. 

was  a  rapid  decline  in  the  growing  of  this  grain  in  northern  Illinois. 
It  seems  possible  thai  spring  wheal  might  be  more  liable  to  attack 
from  chinch  bugs  than  fall  wheat,  as  the  former  is,  at  the  time  when 
chinch  bugs  seek  out  their  breeding  grounds,  more  tender  and  inviting 
than  the  latter.  Mr.  Walter  Young,  writing  from  Galesville,  Wis., 
states  that  his  spring  wheat  was  totally  destroyed  in  ls'>7.  though 
there  had  been  none  sown  for  ten  year-  previous  on  the  premises,  and 
while  the  ehineh  bugs  did  not  ordinarily  do  much  injury,  just  a-  soon 
a-  spring  wheat  was  -own  they  returned,  as  it  were,  and  destroyed  it. 

If  spring  wheat  is  so  attractive  to  chinch  bugs  in  spring  as  this 
would  indicate,  might  it  not  be  used  for  baits  instead  of  millet,  a-  is 
advised  further  on.  in  order  to  draw  oft'  the  females  in  spring  when 
seeking  localities  for  oviposition  I 

This  was  in  a  country  where  there  was  comparatively  little  timber, 
the  only  forests,  if  such  they  could  be  called,  being  along  the  streams 
of  waiter..  The  writer  is  confident  that  the  chinch  bug  did  not  sud- 
denly make  its  appearance  in  that  section,  but  that  with  the  increase 
of  grain  growing  and  the  decrease  of  prairie  fires  its  effects  began  to 
be  more  and  more  marked.  Since  then  Prof.  S.  A.  Forbes  has  secured 
information  of  the  occurrence  of  these  insects  in  sufficient  numbers 
to  attract  attention  as  early  as  1823  in  southern  Illinois,  and  within 
25  miles  of  New  Harmony.  Ind.,  where  Thomas  Say  resided  and  did 
the  most  of  his  entomological  work. 

REASONS    FOR    THE    PRESENT    THEORY    OF    DIFFUSION. 

It  seems  to  the  writer  that  in  all  of  this  we  have  good  grounds 
for  supposing  that  the  chinch  bug  occupied  the  most  of  the  country 
prior  to  its  occupancy  by  the  Avhite  man.  and  that  its  first  depreda- 
tions were  caused  by  its  own  advance  coming  in  contact  with  the 
advance  of  civilization;  and  the  simultaneous  cessation  of  fore>t  and 
prairie  fires,  with  the  displacement  of  the  native  gras>es  by  large 
areas  of  wheat,  so  combined  that  the  points  of  contact  were  in  Illi- 
nois in  the  West  and  Virginia  and  Xorth  Carolina  in  the  East.  Xot 
until  within  the  last  twenty-four  years  has  the  chinch  bug  been 
known  to  work  serious  and  widespread  injury  east  of  the  Allegheny 
Mountains,  north  of  Virginia  :  and  west  of  these  mountains  they  have 
done  scarcely  any  damage  north  and  east  of  a  line  drawn  from 
Chicago  southeast  to  Cincinnati.  Thousands  of  farmers  in  Ohio 
never  -aw  a  chinch  bug  until  within  the  last  thirteen  year.-,  and  there 
are  thousands  more  in  northwestern  Ohio,  southern  Michigan,  and 
northern  Indiana  that,  even  yet.  would  not  be  able  to  recognize  one 
were  they  to  see  it  among  their  growing  grain,  or  even  if  in  abund- 
ance. I > 1 1 1  in  considering  this  matter  the  fact  must  be  borne  in 
mind  that  timothy  meadows  are  not  burned  over  annually  as  were  the 


PROBABLE    ORIGIN    AND    DIFFUSION.  89 

forests  and  prairies,  and  the  stubble  does  not  die  with  the  harvesting 
of  the  crop  as  in  wheat,  and  therefore  annual  migrations  are  noi 
necessary  for  the  bugs  in  order  to  preserve  life.  In  a  timothy 
meadow  the  species  may  live  on  and  reproduce  year  after  year  with 
out  ever  being  obliged  to  abandon  the  field.  It  was  the  wheat  fields 
of  the  Wesl  that  the  eastbound  macropterous  tide  of  migration  found 
confronting  it  in  Illinois,  and  the  smaller  fields  of  grain  and  timothy 
meadows  that  the  combined  macropterous  and  brachypterous  forms, 
more  or  less  maritime  and  northbound,  came  in  contact  with  along 
the  Atlantic  coast,  while  at  the  present  time  the  two  tide-  of  migra- 
tion have  met  in  northeastern  Ohio  ami  northern   Indiana. 

In  figure  17  is  illustrated  the  theoretical  directions  and  courses 
taken  by  each  of  these  tides  of  migrations  from  the  tropical  regions, 
and  in  figure  1  the  areas  over  which  the  species  is  now  known  to 
OCClir  in  Central  and   North  America  are  indicated. 

The  writer  believes  that  this  same  course  of  migration  has  been 
pursued,  at  least  in  the  AYest,  by  the  several  species  of  Diabrotica, 
and  especially  1>.  longicornis  Say.  and  to  a  les^  extent  by  another 
species  of  Hemiptera,  Murgantia  histrionica  Ilahn  and  possibly  also 
by  Dynastes  tityus  L.,  while  the  two  latter  with  others  are  now 
working  northward  along  the  Atlantic  coast.  Besides,  the  westward 
tide  of  migration  lias  been  followed  in  all  probability  by  Pontia  rapa 
L.,  Phytonomus  j>nn<-t<itus  Fab.,  Hylastinus  <>l>s<-tii-us  Marshm.,  and 
Crioceris  asparagi  L.,  all  of  which  have  first  become  destructively 
abundant  west  of  the  Allegheny  Mountains  in  extreme  northeastern 
Ohio.  The  last  four  species,  having  been  introduced  from  Europe, 
have  undoubtedly  migrated  westward. 

With  an  almost  total  lack  of  natural  enemies  in  the  United  States, 
and  with  nearly  all  of  its  closest  allies  belonging  in  Mexico  and  the 
Wesl  Indie-,  it  would  seem  as  though  we  were  in  possession  of  addi- 
tional evidence  of  the  chinch  bug's  tropical  origin.  Besides  this  the 
name  "chinch  bug"  is  of  Spanish  origin,  and  this  language  has 
never  been  in  common  use  in  North  America  except  in  Florida  and 
the  country  along  the  Mexican  border. 

The  species  certainly  prefers  the  low  country  to  the  higher,  and  is 
seldom  found  in  any  numbers  at  an  altitude  of  over  -J .000  feet.  Gen- 
erally its  habitat  is  1  .ooo  or  lower.  The  altitude  where  it  was 
found  breeding  on  Yolcan  de  Chiriqui,  in  Panama,  is  6,000  feet  :  and 
of  its  habitations  in  Guatemala,  San  Geronimo,  is  3,000  feet;  Panzos, 
2,000  feet:  Champerico,  sea  level,  and  Rio  Naranjo.  about  ii.000  feet, 
while  in  Colorado  it  occurs  sparingly  near  Fori  Collins  at  an  eleva- 
tion of  5,500  to  6,000  feet,  while  Professor  Cockerel]  did  not  find  it  at 
all  in  the  -nine  State  at  elevations  of  7,000  to  8,000  feet.  On  Mount 
Washington,  in  New  Hampshire,  it  ha-  been  found  only  once,  and  this 


90  THE    CHINCH    BUG. 

time  1>\  Doctor  Packard,  on  the  summit,  which  has  an  elevation  of 
6,500  feet.0 

In  his  own  experience,  running  over  something  like  forty-live 
year-,  the  writer  has  never  witnessed  serious  injury  by  chinch  bugs 
to  crop-  on  hilly  land.  It  may  be  stated,  however,  that  all  of  his 
studies  of  tie1  insect  have  been  carried  on  in  a  level  country.  Ohio 
being  the  most  uneven  and  hilly,  but  even  here  all  of  the  outbreaks 
observed  were  on  level  areas.  In  Minnesota,  however.  Doctor  Lugger 
found  that  those  grain  field-  which  were  most  seriously  injured 
were  located  near  the  edges  of  woods  or  on  slopes.  In  some  pub- 
lished observations  of  Professor  Osborn,  in  Iowa,  kindly  placed 
at  the  writer'-  disposal  by  Doctor  Howard,  we  find  that  in  1894  about 
'.'<)  per  cent  of  the  infested  field-  examined  by  Profe>>or  Osborn  were 
on  high  ground  and  about  SO  per  cent  of  the  fields  were  hilly  and 
ridges,  in  most  cases  the  damage  being  first  apparent  upon  the 
higher  portions  of  the  fields.  The  exception-  were  where  the  chinch 
bug  had  evidently  hibernated  in  wild  grass  and  weeds  occurring  in 
the  lower  places,  and  these  had  been  very  dry  for  the  twelve  months 
preceding  the  damage  of  that  year.  Besides,  both  the  Iowa  and 
Minnesota  areas  are  below  1.000  feet  elevation. 

The  area  over  which  the  chinch  bug  is  more  especially  abundant 
and  destructive  comprises  such  a  variety  of  soils  and  geological 
formations  that  a  study  of  these  factors  at  once  shows  that  neither 
has  any  material  influence  in  the  distribution  of  the  species,  at  least 
in  the  United  States.  In  its  northernmost  habitat  it  would  not  be 
,;t  all  surprising  that  it  should  prefer  a  sandy,  rather  than  a  clay, 
soil,  the  former  being  looser  and  warmer  on  or  near  the  surface. 
(See  fig.  10.) 

In  conclusion,  then,  on  this  point  it  may  be  stated  that  if  Blissus 
leucopterus  originated  in  the  Western  Hemisphere  it  was  probably 
near  the  Tropics,  and  it  i-  not  impossible  that  it-  generic  ancestors 
may  have  been  carried  from  Europe  or  Africa  by  either  the  north 
equatorial  or  the  main  equatorial  Atlantic  currents,  landing  them 
on  the  northern  shores  of  South  America  or  on  some  closely  located 
islands,  from  which  the  species  ha-  spread  coastwise  around  the 
Caribbean  Sea  and  the  Gulf  of  Mexico,  a-  previously  indicated.  In 
thi-  connection  it  is  interesting  to  note  that  specimens  from  Grenada, 
collected  on  the  Mount  Joy  and  Caliveny  estates  by  Mr.  II.  II.  Smith 
in  June  and  September,  -how  that  the  species  here  attain.-  a  large 
size  and  i-  more  variable,  both  in  size  and  markings,  than  is  com- 
monly found  to  be  the  case  in  the  eastern  United  States. 

See  paper  by  the  writer  on  Origin  and  Diffusion  of  Blissus  leucopterus  and 
Murfjantia  histrionica,  in  Journal  of  Cincinnati  Society  of  Natural  History.  Vol. 
Will.  February,  L896. 

''I'liler  on  Hemiptera-Heteroptera  from  St.  Vincent  and  Grenada.  Proe.  Zool. 
Soc,  London,  1894. 


N  n  E  X 


Page. 

Agonoderus  pallipes,  enemy  of  chinch  bug         60 

Amaranth,  food  planl  of  Vysius  angustatus 32 

IntJiocoris  pseudo-chinche      Triphleps  insidiosus      GO 

Ants,  enemies  of  chinch  bug 00 

Aphides,  Entomophthora  aphidis  a  fungus  enemy -IT 

Aphodius  inqu hiatus,  migrating  habit 19 

serval,  migrating  habit 1!) 

Arrhenatherum,  food  planl  <>t'  chinch  bug 31 

Bacillus  insectorum,  bacterial  enemy  of  chinch  bus 57 

Bacteria]  enemies  of  chinch  bug 57,58 

Barley,  food  plant  of  chinch  bug 31 

Barriers,  use  againsl  chinch  lmu 05-00,72 

Blackbird,  redwing,  enemy  of  chinch  bug 59 

Blissus,  distribution   of  genus 9 

dorice,  habits 83-87 

migratory  habit  contrasted  with  that  of  chinch  bug 19 

no  disinclination  to  use  wings,  as  with  chinch  bug 24 

leucopterus.     (See  also  Chinch  bug.) 

locality  records 9-10 

Bluegrass.     <  See  ]'<>«  pratensis.  I 
Bobwhite.     (See  Colinus  virginianus.) 

Botrytis,  Sporotrichum  globuliferum  closely  allied 53 

wrong  determination  of  Sporotrichum  globuliferum 46 

Brachyrhynchus  granulatus,  mistaken  for  chinch  bug 32-33 

Buckwheat,  wild,     i  See  Polygonum  dumeiorum  or  P.  convolvulus. ) 

Burning  over  to  destroy  chinch  bug 61-62,72 

Cabbage  bug,  harlequin,     i  See  Murgantia  histrionica.) 

Capriola  dactylon,  \'<h><\  plant  of  chinch  bug 31 

Carpocapsa  pomonella,  change  of  habits  in  South  Australia 20 

Catbird,  enemy  of  chinch  bug 59 

Cenchrus,  only  grass  not  attacked  by  chinch  bus 13 

Chinch  bug.     (See  also  Blissus  leucopterus.) 

adult,    description 22 

appearance   unique     71-75 

bacterial    enemies 57.  58 

behavior  when  attacked  by  Sporotrichum  globuliferum 55 

benefit   alleged  therefrom . 29 

bird   enemies 58-59 

descriptions  of  stages 21-22 

destructiveness  largely  due  to  gregarious  habits 28  29 

development ' 22-25 

diffusion,  previous  ideas 87 

probable  course—                                             - 78-83 

reasons  for  present  theory—    _     .    88-90 

91 


92  INDEX. 

Pag 

Chinch  bug,  distribution,  geographical (.ci<> 

vertical '.. 

effect  of  cold  and  wet  weather is 

freezing    17-18 

__.   description 21 

period    20  21 

•     eggs,  number  deposited 20-21 

false,     i  See  Kysius  angustatus.) 

food   plants 29-31 

form  from  Grenada  large  and  variable 90 

frog  an  enemy 59 

fungous    enemies 4  1  58 

practical  utility 58 

generations    annually 25-28 

gregarious    habit 74-7." 

habits  account  largely  for  destructiveness 28-29 


habits  of  younj 


•>■>_•> 


hibernation    lo-is 

influence  of  precipitation 36-43 

temperature    43-44 

insects  mistaken  therefor :;i-."»."» 

invertebrate  enemies 60 

larval  stages,  description 21-22 

long.     (See  Ischnodemus  f aliens.) 

long-winged  form  and  short-winged  form 22 

occurrence  and  dis- 
tribution      75-77 

losses 33-36 

meteorological  influences  favoring  fungous  enemies 56-57 

migration  on  foot  in  search  of  food 24 

migrations  in  spring,  summer,  and  autumn 18-20 

name  of  Spanish  origin 89 

natural   checks 30-44 

enemies 44-i;n 

origin  and  diffusion,  probable 72-1  h  i 

oviposition 20-21 

pupa,  description 22 

remedial  and  preventive  measures 60-72 

short-winged,  relation  of  inland  and  sea coast  forms 7S 

Chrysopa,  enemies  of  chinch  bug •'■<» 

Clover-leaf  weevil.      (See  Phytonomus  punctatus.) 

Coal  tar.  use  in  barriers  against  chinch  bug 65-68 

Codling  moth.     (See  Carpocapsa  pomonella.) 

Colinus  uirginianus,  enemy  of  chinch  bug 58  59 

ConotracJielus  nenuphar,  migrating  habit 10 

Corimelasna  pulicaria,  mistaken  for  chinch  bug .".2 

Corn,  broom,  food  plant  of  chinch  bug .".1 

chicken,  food  plant  of  chinch  bug 31 

food  plant  of  chinch  bug 30 

Cow  blackbirds,  decrease  held  responsible  for  increase  of  chinch  bugs 13 

Crab  grass,  occurrence  of  half-grown  chinch  bugs  in  fall 1<» 

Crioceris  asparagi,  course  of  diffusion 89 


INDEX.  93 

Cyniodcma  tabida,  mistaken  for  chinch  Mil: 

Decoy  plats  of  grains  and  grasses,  In  combating  chinch  bug  62,72 

Diabrotica,  course  of  diffusion     89 

longicomis      7<*» 

course  of  diffusion 80 

Dimorphism,  in  Blissus  doriw 84 

chinch  bug   22,75  77 

Dispersal  of  insects,  effected  by  storms  19,20 

Distribution,  geographical,  of  chinch  bug 9   10 

vertical,  of  chinch  bug 89  90 

Droughl  necessitates  watchfulness  againsl  chinch  bug »;.".  <;i 

Dynastes  tityus,  course  of  diffusion 89 

Eciton  liiiiiiiit urn.  enemy  of  chinch  bug 25 

Etnpusa  aphidis       Entomophthora  aphidis 17 

Entomophthoi  a  aphidis,  fungous  enemy  of  aphides 17 

chinch  bug 1 1.  17 

sjijui  rospt  rum,  fungous  enemy  of  Phytonomus  punctatus  55 

Epicauta  pennsylvanica,  attacked  by  Sporotrichum  globuliferum  •""••"'> 

Tiros,  prairie,  relation  to  numbers  of  chinch  bugs 87  89 

Fl ling,  in  destroy  chinch  bug 69 

Flower  bug,  insidious.     (See  Triphleps  insidiosus.) 

Freezing,  eflfecl  on  chinch  bug 17   L8 

Frog,  enemy  of  chinch  bug 59 

Fungous  enemies  of  chinch  bug -1  f  58 

determination 4»;    17 

field  and  laboratory  experiments  in  Indiana.   47-.~><» 

first  field  applications 51 

meteorological  influences  favoring  develop- 
ment  '. 56  57 

practical    utility *        58 

work  of  Professor  Snow  in  Kansas -".1    53 

Geocoris borealis,  mistaken  for  chinch  bug 32 

bullatus,  mistaken  for  chinch  bug 32 

fuliginosus,  mistaken  for  chinch  bug 32 

limbiif us,  mistaken  for  chinch  bug- 32 

Grain,  all  kinds,  food  plants  of  chinch  hug 30 

Grass,  Bermuda.     (See  Capriola  dactylon.) 
blue,     i  Sec  Poa  pi  atensis.  I 
botl  le.     i  Sec  Ixophorus  viridis.  i 
crab,     i  See  Syntherisma  sanguinalis.) 
meadow  foxtail.     I  See  Ixophorus  glaucus.) 
oat.     i  s<  i   Arrhenatherum.  i 
panic,     i  Sec  Panicum  crus-galli.  I 

Grasses,  all  but  Cenchrus  attacked  by  chinch  bug L3 

••  Hair  snake."     I  6f<  i    Mermis.  i 
Herd's  grass.     (S(  e  Timothy,  i 

Hibernation  of  chinch  bug 1(l   L8 

Hungarian  grass,  food  planl  of  chinch  buur 29 

Hylastinus  obscurus,  course  of  diffusion 89 

insects,  dispersal  effected  by  storms 19,20 

Ischnodemus  faliCUS,  mistaken   lot-  chinch  hug '.V2 

l8Chnorhynchu8  didymus,  mistaken  for  chinch  hug :v2 


CJ4  [NDEX. 

Page. 

Ixophorus  glaucus,  food  plant  of  chinch  bng 29 

viridis,  food  plant  of  chinch  bng 31 

Juncus,  place  of  hibernation  of  chinch  bugs 15 

Kerosene  emulsion,  use  againsl  chinch  bug 64-65, 72 

use  against  chinch  bug 64-65 

"  Killdees,"  observed  feeding  on  chinch  hugs 13 

Lace- wing  flies.     (Set  Chrysopa.) 

Lachnosterna,  attacked  by  Sporotrichum  globuliferum 53 

Lady-beetles,  enemies  of  chinch  bug <;n 

Lark,  horned,  enemy  of  chinch  hug 

"Larks,"  observed  feeding  on  chinch  bugs 13 

Leaf-bug,  ash-gray.     1  See  Piesma  cim  r<  a.  \ 

Ligyrocoris  sylvestris,  mistaken  for  chinch  hug 32 

Losses   from  chinch  bug :;:;-:;•; 

.Marlins,  decrease  held  responsible  for  increase  of  chinch  bugs 13 

Meadowlark,  enemy  of  chinch  bug 59 

Meadows,  difficulty  of  combating  chinch  bug  therein 62-63 

Megitta   maculata  attacked  by  Sporotrichum  globuliferum 53 

Mermis,  parasite  of  chinch   hug 60 

Meterological  influences  favoring  fungous  enemies  of  chinch  bug 56-57 

Migrations  of  chinch  bug  1&-20 

pedestrian 24- 2s 

Millet,  food  plant  of  chinch  bug 29 

Mil inis  ductus,  enemy  of  chinch  bug 60 

Monocrepidius,  attacked  by  Sporotrichum  globuliferum 

•'  .Mormon  lice."  early  local  name  for  chinch  bugs ^7 

Murgantia  histrionica,  course  of  diffusion- 89 

not  attacked  by  Sporotrichum  globuliferum 53 

Kaupactus  xanthographus,  attacked  by  Sporotrichum  globuliferum 

Negro. bug,  flea-like.     (See  Corimelaena  pulicaria.) 

Nysius  angustatus,  mistaken  for  chinch  bug 1 ?>1-:J2 

Oats,  i'ood  plant  of  chinch  hug 'M 

Oviposition  of  chinch  hug , 20-21 

Panicum  crus-galli,  food  plant  of  chinch  ling 29 

Parandra  brunnea,  attacked  by  Sporotrichum  globuliferum 

'•  Partridges,"  decimation  held  responsible  for  increase  of  chinch  hugs 13 

Pasturing,  remedy  for  chinch  hug 62 

Peliopelta  abbreviata,  mistaken  for  chinch  hug .".2 

Phleum  pratense.     {See  Timothy.) 

Phytonomus  punctatus,  behavior     when     attacked     by     Entomophthora 

sphcrrospi  rma    55 

course  of  diffusion 89 

Piesma  cinerea,  mistaken  for  chinch  hug 

Plowing  furrows,  barriers  against  chinch  hug 69,  72 

to  destroy   chinch   hug *'.•';.  72 

Plum  curculio.     1  Sec  Conotrachelus  nenuphar.) 

Poa  pratensis,  food  plant  of  chinch  bug . 31 

Polygonum  dumetorum  or  /'.  convolvulus,  food  plant  of  chinch  hug •".! 

Pontia  ni/xt.  course  of  diffusion 89 

Prairie  chicken,  enemy  of  chinch  bug 13,59 

Precipitation,  influence  on  chinch  bug 36—13 

Preventive  measures  against  chinch  bug,  difficulty  in  practice d'.t-Tl 


[NDEX.  95 

Purslane,  food  plant  of   Vysius  angustatus :;-j 

Quail.       (Sec    Colin  us    riniiiiiuii  us.  \ 

Rain,     i  See  Precipitation.  > 

Rice,   food  planl   of  chinch   bug                                                 :;i 

Rushes,     i  8* '   Juncus. ) 

K\ e,  food  plant  of  chinch  bug      __  .".i 

Salton  Basin,  occurrence  of  chinch  bug      29 

Sand  oats.     <  See  /  niola  paniculata.  i 
Setaria  glauca.     (See  Ixophorus  glaucns.) 

Sorghum,   food   plain   of  chinch  bug 31 

••  sparrows,  bank,"  decrease  held  responsible  for  increase  of  chinch  bugs  60 

Spider  welts,  occurrence  of  chinch  bugs GO 

Sporotrichum  globuliferum,  first  artificial  cultivations 51 

insc.-ts  attacked 53 

parasitic  on  chinch  bug II.  Hi.  IT.'.:: 

results  of  field  applications  in  Ohio r. i  :.i, 

use  against  chinch  bugs 64,72 

Storms.  Influence  in  dispersal  of  insects 19,20 

Swallow,  tree,  enemy  of  chinch  bug      59 

suiil/n  risnid  sanguinalis,  food  plant  of  chinch  bug :'.! 

Temperature,   influence  on  chinch  bug - 43    i  I 

Thrush,  brown,  enemy  of  chinch  bug 5'J 

Timothy,   food   plant  of  chinch  bug ^ 23,30,31 

Trap  crops     i  8(  e  I  >ecoy  plats.  > 

Trapezonotus  nebulosus,  mistaken  for  chinch  bug '•'>- 

Triphleps  insidiosus,  enemy  of  chinch  bug 60 

mistaken    for  chinch   bug 32 

/  niola  paniculata,  abnormal  habit  of  chinch  bug  thereon 23,76 

Wheat,  food  plant  of  chinch  bug '-'>\ 

Wren,  house,  enemy  of  chinch  bug 59 


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